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@@ -16,3 +16,69 @@ GRANT ALL PRIVILEGES ON prospectwith.* TO 'power'@'localhost' WITH GRANT OPTION;
|
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CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password'; # Create user
|
||||
|
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mysql -u root -pmypassword -e "MY SQL QUERY" &>> query.log & disown # Run SQL query in the background
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# *****************************************************************************
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# Database and Table Operations
|
||||
# *****************************************************************************
|
||||
|
||||
CREATE DATABASE database_name; # Create a new database
|
||||
DROP DATABASE database_name; # Delete a database
|
||||
CREATE TABLE table_name (column1 datatype, column2 datatype, ...); # Create a new table
|
||||
DROP TABLE table_name; # Delete a table
|
||||
SHOW TABLES; # Display all tables in the current database
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||||
DESCRIBE table_name; # Show the structure of a table
|
||||
|
||||
# *****************************************************************************
|
||||
# Data Manipulation
|
||||
# *****************************************************************************
|
||||
|
||||
INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...); # Insert data into a table
|
||||
UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; # Update existing data in a table
|
||||
DELETE FROM table_name WHERE condition; # Delete data from a table
|
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SELECT column1, column2, ... FROM table_name WHERE condition; # Select data from a table
|
||||
|
||||
# *****************************************************************************
|
||||
# Backup and Restore
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||||
# *****************************************************************************
|
||||
|
||||
mysqldump -u username -p database_name table1 table2 > file.sql # Backup specific tables
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mysql -u username -p database_name < file.sql # Restore specific tables
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||||
|
||||
# *****************************************************************************
|
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# User Management and Security
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# *****************************************************************************
|
||||
|
||||
REVOKE privilege_type ON database_name.table_name FROM 'username'@'hostname'; # Revoke privileges from a user
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DROP USER 'username'@'hostname'; # Delete a user
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ALTER USER 'username'@'hostname' IDENTIFIED BY 'newpassword'; # Reset a user's password
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# *****************************************************************************
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# Performance and Maintenance
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# *****************************************************************************
|
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|
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OPTIMIZE TABLE table_name; # Optimize a table
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ANALYZE TABLE table_name; # Analyze a table for key distribution and storage optimization
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CHECK TABLE table_name; # Check a table for errors
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REPAIR TABLE table_name; # Repair a corrupted table
|
||||
|
||||
# *****************************************************************************
|
||||
# Advanced Queries
|
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# *****************************************************************************
|
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|
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SELECT ... FROM table1 JOIN table2 ON table1.column = table2.column; # Perform a join operation between two tables
|
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SELECT ... FROM (SELECT ... FROM table_name) AS subquery; # Use a subquery within another query
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SELECT column, COUNT(*) FROM table_name GROUP BY column; # Group results and use aggregate functions
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|
||||
# *****************************************************************************
|
||||
# System Information
|
||||
# *****************************************************************************
|
||||
|
||||
SELECT VERSION(); # Show the current version of MySQL
|
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SELECT User, Host FROM mysql.user; # List all current MySQL users
|
||||
|
||||
# *****************************************************************************
|
||||
# Miscellaneous
|
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# *****************************************************************************
|
||||
|
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SET GLOBAL general_log = 'ON'; # Enable query logging
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SHOW FULL PROCESSLIST; # Show the last queries executed in MySQL
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|
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@@ -88,7 +88,7 @@ CHEATSHEET C#
|
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string newStr = oldStr.Replace("old","new");
|
||||
|
||||
//IndexOf
|
||||
//Finds the first ocurrence of a string in a larger string
|
||||
//Finds the first occurrence of a string in a larger string
|
||||
//Returns -1 if the string is not found
|
||||
String.IndexOf(val, start, num)
|
||||
val - string to search for
|
||||
@@ -102,7 +102,7 @@ CHEATSHEET C#
|
||||
String.Split(Char[]);
|
||||
|
||||
//ToCharArray
|
||||
//Places selected characteres in a string in a char array
|
||||
//Places selected characters in a string in a char array
|
||||
String str = "AaBbCcDd";
|
||||
//create array of 8 vowels
|
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var chars = str.ToCharArray();
|
||||
@@ -135,7 +135,7 @@ CHEATSHEET C#
|
||||
|
||||
6.1 TimeSpan Constructor
|
||||
|
||||
TimpeSpan(hour, minute, sec)
|
||||
TimeSpan(hour, minute, sec)
|
||||
|
||||
TimeSpan timeS = new TimeSpan(10, 14, 50);
|
||||
TimeSpan timeS_Hours = TimeSpan.FromDays(3640);
|
||||
@@ -144,8 +144,8 @@ CHEATSHEET C#
|
||||
|
||||
Format item syntax: {index[,alignment][:format string]}
|
||||
index - Specifies element in list of values to which format is applied
|
||||
aligment - Indicates minimun width (in characters) to display value
|
||||
format string - Contains the code which specififes the format of the displayed value
|
||||
alignment - Indicates minimum width (in characters) to display value
|
||||
format string - Contains the code which specifies the format of the displayed value
|
||||
|
||||
7.1 Numeric
|
||||
|
||||
@@ -293,7 +293,7 @@ CHEATSHEET C#
|
||||
[access modifier] className (parameters) [:initializer]
|
||||
|
||||
initializer -base calls constructor in base class.
|
||||
this calls constuctor within class.
|
||||
this calls constructor within class.
|
||||
|
||||
public class nameClass : Initializer {
|
||||
public className(dataType param1 , dataType param2, ...) : base(param1, param2)
|
||||
@@ -313,8 +313,8 @@ CHEATSHEET C#
|
||||
abstract – must be implemented by subclass
|
||||
|
||||
Passing parameters:
|
||||
1. By default, parametres are passed by value
|
||||
2. Passing by reference: ref, in and out modifers
|
||||
1. By default, parameters are passed by value
|
||||
2. Passing by reference: ref, in and out modifiers
|
||||
|
||||
To pass a parameter by reference with the intent of changing the value, use the ref, or out keyword. To pass by reference with the intent of avoiding copying but not changing the value, use the in modifier
|
||||
|
||||
|
||||
@@ -524,14 +524,14 @@ Cyan='\033[0;36m' # Cyan
|
||||
White='\033[0;97m' # White
|
||||
|
||||
# Additional colors
|
||||
LGrey='\033[0;37m' # Ligth Gray
|
||||
LGrey='\033[0;37m' # Light Gray
|
||||
DGrey='\033[0;90m' # Dark Gray
|
||||
LRed='\033[0;91m' # Ligth Red
|
||||
LGreen='\033[0;92m' # Ligth Green
|
||||
LYellow='\033[0;93m'# Ligth Yellow
|
||||
LBlue='\033[0;94m' # Ligth Blue
|
||||
LRed='\033[0;91m' # Light Red
|
||||
LGreen='\033[0;92m' # Light Green
|
||||
LYellow='\033[0;93m'# Light Yellow
|
||||
LBlue='\033[0;94m' # Light Blue
|
||||
LPurple='\033[0;95m'# Light Purple
|
||||
LCyan='\033[0;96m' # Ligth Cyan
|
||||
LCyan='\033[0;96m' # Light Cyan
|
||||
|
||||
|
||||
# Bold
|
||||
|
||||
@@ -397,8 +397,8 @@ d, t := doubleAndTriple(5)
|
||||
_, t := doubleAndTriple(3)
|
||||
// t = 9
|
||||
|
||||
// Functions can defer commands. Defered commands are
|
||||
// runned in a stack order after the execution and
|
||||
// Functions can defer commands. Deferred commands are
|
||||
// ran in a stack order after the execution and
|
||||
// returning of a function
|
||||
var aux = 0
|
||||
|
||||
@@ -488,7 +488,7 @@ person3.Age // 0
|
||||
|
||||
## Maps
|
||||
|
||||
Maps are data structures that holds values assigneds to a key.
|
||||
Maps are data structures that holds values assigned to a key.
|
||||
|
||||
```go
|
||||
// Declaring a map
|
||||
@@ -508,7 +508,7 @@ newYork // "EUA"
|
||||
// Delete
|
||||
delete(cities, "NY")
|
||||
|
||||
// Check if a key is setted
|
||||
// Check if a key is set
|
||||
value, ok := cities["NY"]
|
||||
ok // false
|
||||
value // ""
|
||||
|
||||
@@ -308,7 +308,7 @@ for(dataType item : array) {
|
||||
//Declare a variable, object name
|
||||
String s;
|
||||
|
||||
//Invoke a contructor to create an object
|
||||
//Invoke a constructor to create an object
|
||||
s = new String ("Hello World");
|
||||
|
||||
//Invoke an instance method that operates on the object's value
|
||||
|
||||
@@ -95,3 +95,9 @@ arr.reduce(callback[, initialValue]) // Apply a function against
|
||||
arr.reduceRight(callback[, initialValue]) // Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value.
|
||||
arr.some(callback[, initialValue]) // Returns true if at least one element in this array satisfies the provided testing function.
|
||||
arr.values() // Returns a new Array Iterator object that contains the values for each index in the array.
|
||||
|
||||
// String methods
|
||||
String.charAt(index) // Returns the character at the specified index in a string.
|
||||
String.indexOf(character) // Returns the index of the first occurrence of a specified value in a string.
|
||||
String.substring(starting_index, ending_index) // Returns a new string that is a subset of the original string.
|
||||
String.substring(starting_index) // Returns a substring from starting index to last index of string.
|
||||
@@ -1,8 +1,8 @@
|
||||
<?php
|
||||
|
||||
// Exit the file, string inside get's echo'ed
|
||||
die("This file is not ment to be ran. ¯\_(ツ)_/¯");
|
||||
exit("This file is not ment to be ran. ¯\_(ツ)_/¯");
|
||||
die("This file is not meant to be ran. ¯\_(ツ)_/¯");
|
||||
exit("This file is not meant to be ran. ¯\_(ツ)_/¯");
|
||||
|
||||
/**
|
||||
* Printing
|
||||
@@ -17,7 +17,7 @@ var_dump($arr); // Print anything, with type hints for any value and sizes
|
||||
$string = 'Awesome cheatsheets';
|
||||
|
||||
str_contains($string, 'cheat'); // Find if the string contains the specified string (PHP >= 8.0)
|
||||
str_replace('Awesome', 'Bonjour', $string); // Replace all occurence
|
||||
str_replace('Awesome', 'Bonjour', $string); // Replace all occurrence
|
||||
strcmp($string, 'Awesome cheatsheets'); // Compare two strings
|
||||
strpos($string, 'a', 0); // Get position in the string
|
||||
str_split($string, 2); // Split the string
|
||||
@@ -541,7 +541,7 @@ u Pattern is treated as UTF-8
|
||||
\w Any "word" character (a-z 0-9 _)
|
||||
\W Any non "word" character
|
||||
\s Whitespace (space, tab CRLF)
|
||||
\S Any non whitepsace character
|
||||
\S Any non whitespace character
|
||||
\d Digits (0-9)
|
||||
\D Any non digit character
|
||||
. (Period) - Any character except newline
|
||||
|
||||
@@ -71,7 +71,7 @@
|
||||
| import | import libraries/modules/packages | import |
|
||||
| from | import specific function/classes from modules/packages | import |
|
||||
| try | this block will be tried to get executed | exception handling |
|
||||
| except | is any exception/error has occured it'll be executed | exception handling |
|
||||
| except | is any exception/error has occurred it'll be executed | exception handling |
|
||||
| finally | It'll be executed no matter exception occurs or not | exception handling |
|
||||
| raise | throws any specific error/exception | exception handling |
|
||||
| assert | throws an AssertionError if condition is false | exception handling |
|
||||
|
||||
379
tools/NumPy.md
379
tools/NumPy.md
@@ -1,379 +0,0 @@
|
||||
# NumPy Cheat Sheet
|
||||
|
||||
[NumPy](http://www.numpy.org) is the fundamental package for scientific computing with Python.
|
||||
|
||||
### Installation
|
||||
If you don't already have it **installed**, you can do so using Pip or Anaconda:
|
||||
```
|
||||
$ pip install numpy
|
||||
```
|
||||
or
|
||||
```
|
||||
$ conda install numpy
|
||||
```
|
||||
|
||||
This cheat sheet acts as a intro to Python for data science.
|
||||
|
||||
## Index
|
||||
1. [Basics](#basics)
|
||||
- [Placeholders](#place)
|
||||
- [Examples](#ex)
|
||||
2. [Arrays](#arrays)
|
||||
- [Properties](#props)
|
||||
- [Copying/Sorting](#gops)
|
||||
* [Examples](#array-example)
|
||||
- [Array Manipulation](#man)
|
||||
* [Adding/Removing Elements](#addrem)
|
||||
+ [Examples](#array-elements-examples)
|
||||
* [Combining Arrays](#comb)
|
||||
+ [Examples](#array-combine-examples)
|
||||
* [Splitting Arrays](#split)
|
||||
+ [Examples](#array-split-examples)
|
||||
* [Shaping](#shape)
|
||||
* [Misc](#misc)
|
||||
3. [Mathematics](#maths)
|
||||
- [Arithmetic Operations](#ops)
|
||||
* [Examples](#operations-examples)
|
||||
- [Comparison](#comparison)
|
||||
* [Examples](#comparison-example)
|
||||
- [Basic Statistics](#stats)
|
||||
* [Examples](#stats-examples)
|
||||
- [More](#more)
|
||||
4. [Slicing and Subsetting](#ss)
|
||||
- [Examples](#exp)
|
||||
5. [Tricks](#tricks)
|
||||
6. [Credits](#creds)
|
||||
|
||||
</br>
|
||||
|
||||
## Basics <a name="basics"></a>
|
||||
|
||||
One of the most commonly used functions of NumPy are *NumPy arrays*: The essential difference between *lists* and *NumPy arrays* is functionality and speed. *lists* give you basic operation, but *NumPy* adds FFTs, convolutions, fast searching, basic statistics, linear algebra, histograms, etc.</br>
|
||||
The most important difference for data science is the ability to do **element-wise calculations** with *NumPy arrays*.
|
||||
|
||||
`axis 0` always refers to row </br>
|
||||
`axis 1` always refers to column
|
||||
|
||||
| Operator | Description | Documentation |
|
||||
| :------------- | :------------- | :--------|
|
||||
|`np.array([1,2,3])`|1d array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.array.html#numpy.array)|
|
||||
|`np.array([(1,2,3),(4,5,6)])`|2d array|see above|
|
||||
|`np.arange(start,stop,step)`|range array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.arange.html)|
|
||||
|
||||
### Placeholders <a name="place"></a>
|
||||
| Operators | Description |Documentation|
|
||||
| :------------- | :------------- |:---------- |
|
||||
|`np.linspace(0,2,9)`|Add evenly spaced values btw interval to array of length |[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.linspace.html)|
|
||||
|`np.zeros((1,2))`|Create and array filled with zeros|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.zeros.html)|
|
||||
|`np.ones((1,2))`|Creates an array filled with ones|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ones.html#numpy.ones)|
|
||||
|`np.random.random((5,5))`|Creates random array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.random.random.html)|
|
||||
|`np.empty((2,2))`|Creates an empty array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.empty.html)|
|
||||
|
||||
### Examples <a name="ex"></a>
|
||||
|
||||
```python
|
||||
import numpy as np
|
||||
|
||||
# 1 dimensional
|
||||
x = np.array([1,2,3])
|
||||
# 2 dimensional
|
||||
y = np.array([(1,2,3),(4,5,6)])
|
||||
|
||||
x = np.arange(3)
|
||||
>>> array([0, 1, 2])
|
||||
|
||||
y = np.arange(3.0)
|
||||
>>> array([ 0., 1., 2.])
|
||||
|
||||
x = np.arange(3,7)
|
||||
>>> array([3, 4, 5, 6])
|
||||
|
||||
y = np.arange(3,7,2)
|
||||
>>> array([3, 5])
|
||||
```
|
||||
|
||||
</br>
|
||||
|
||||
## Array <a name="arrays"></a>
|
||||
### Array Properties <a name="props"></a>
|
||||
|Syntax|Description|Documentation|
|
||||
|:-------------|:-------------|:-----------|
|
||||
|`array.shape`|Dimensions (Rows,Columns)|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.shape.html)|
|
||||
|`len(array)`|Length of Array|[link](https://docs.python.org/3.5/library/functions.html#len)|
|
||||
|`array.ndim`|Number of Array Dimensions|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.ndim.html)|
|
||||
|`array.size`|Number of Array Elements|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.size.html)|
|
||||
|`array.dtype`|Data Type|[link](https://docs.scipy.org/doc/numpy/reference/arrays.dtypes.html)|
|
||||
|`array.astype(type)`|Converts to Data Type|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.astype.html)|
|
||||
|`type(array)`|Type of Array|[link](https://docs.scipy.org/doc/numpy/user/basics.types.html)|
|
||||
|
||||
### Copying/Sorting <a name="gops"></a>
|
||||
| Operators | Descriptions | Documentation |
|
||||
| :------------- | :------------- | :----------- |
|
||||
|`np.copy(array)`|Creates copy of array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.copy.html)|
|
||||
|`other = array.copy()`|Creates deep copy of array|see above|
|
||||
|`array.sort()`|Sorts an array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.sort.html)|
|
||||
|`array.sort(axis=0)`|Sorts axis of array|see above|
|
||||
|
||||
#### Examples <a name="array-example"></a>
|
||||
```python
|
||||
import numpy as np
|
||||
# Sort sorts in ascending order
|
||||
y = np.array([10, 9, 8, 7, 6, 5, 4, 3, 2, 1])
|
||||
y.sort()
|
||||
print(y)
|
||||
>>> [ 1 2 3 4 5 6 7 8 9 10]
|
||||
```
|
||||
|
||||
## Array Manipulation Routines <a name="man"></a>
|
||||
|
||||
### Adding or Removing Elements <a name="addrem"></a>
|
||||
|Operator|Description|Documentation|
|
||||
|:-----------|:--------|:---------|
|
||||
|`np.append(a,b)`|Append items to array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.append.html)|
|
||||
|`np.insert(array, 1, 2, axis)`|Insert items into array at axis 0 or 1|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.insert.html)|
|
||||
|`np.resize((2,4))`|Resize array to shape(2,4)|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.resize.html)|
|
||||
|`np.delete(array,1,axis)`|Deletes items from array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.delete.html)|
|
||||
|
||||
#### Example <a name="array-elements-examples"></a>
|
||||
```python
|
||||
import numpy as np
|
||||
# Append items to array
|
||||
a = np.array([(1, 2, 3),(4, 5, 6)])
|
||||
b = np.append(a, [(7, 8, 9)])
|
||||
print(b)
|
||||
>>> [1 2 3 4 5 6 7 8 9]
|
||||
|
||||
# Remove index 2 from previous array
|
||||
print(np.delete(b, 2))
|
||||
>>> [1 2 4 5 6 7 8 9]
|
||||
```
|
||||
|
||||
### Combining Arrays <a name="comb"></a>
|
||||
|Operator|Description|Documentation|
|
||||
|:---------|:-------|:---------|
|
||||
|`np.concatenate((a,b),axis=0)`|Concatenates 2 arrays, adds to end|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.concatenate.html)|
|
||||
|`np.vstack((a,b))`|Stack array row-wise|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.vstack.html)|
|
||||
|`np.hstack((a,b))`|Stack array column wise|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.hstack.html#numpy.hstack)|
|
||||
|
||||
#### Example <a name="array-combine-examples"></a>
|
||||
```python
|
||||
import numpy as np
|
||||
a = np.array([1, 3, 5])
|
||||
b = np.array([2, 4, 6])
|
||||
|
||||
# Stack two arrays row-wise
|
||||
print(np.vstack((a,b)))
|
||||
>>> [[1 3 5]
|
||||
[2 4 6]]
|
||||
|
||||
# Stack two arrays column-wise
|
||||
print(np.hstack((a,b)))
|
||||
>>> [1 3 5 2 4 6]
|
||||
```
|
||||
|
||||
### Splitting Arrays <a name="split"></a>
|
||||
|Operator|Description|Documentation|
|
||||
|:---------|:-------|:------|
|
||||
|`numpy.split()`||[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.split.html)|
|
||||
|`np.array_split(array, 3)`|Split an array in sub-arrays of (nearly) identical size|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.array_split.html#numpy.array_split)|
|
||||
|`numpy.hsplit(array, 3)`|Split the array horizontally at 3rd index|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.hsplit.html#numpy.hsplit)|
|
||||
|
||||
#### Example <a name="array-split-examples"></a>
|
||||
```python
|
||||
# Split array into groups of ~3
|
||||
a = np.array([1, 2, 3, 4, 5, 6, 7, 8])
|
||||
print(np.array_split(a, 3))
|
||||
>>> [array([1, 2, 3]), array([4, 5, 6]), array([7, 8])]
|
||||
```
|
||||
### Shaping Arrays <a name="shape"></a>
|
||||
##### TODO
|
||||
|Operator|Description|Documentation|
|
||||
|:---------|:-------|:------|
|
||||
|`other = ndarray.flatten()`|Flattens a 2d array to 1d|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.flatten.html)|
|
||||
|numpy.flip()|Flips order of elements in 1D array||
|
||||
|np.ndarray[::-1]|Same as above||
|
||||
|reshape|||
|
||||
|squeeze|||
|
||||
|expand_dims|||
|
||||
|
||||
### Misc <a name="misc"></a>
|
||||
|Operator|Description|Documentation|
|
||||
|:--------|:--------|:--------|
|
||||
|`other = ndarray.flatten()`|Flattens a 2d array to 1d|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.flatten.html)|
|
||||
|`array = np.transpose(other)`</br> `array.T` |Transpose array|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.transpose.html)|
|
||||
|`inverse = np.linalg.inv(matrix)`|Inverse of a given matrix|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.inv.html) |
|
||||
</br>
|
||||
|
||||
#### Example <a name="inverse of a matrix"></a>
|
||||
```python
|
||||
# Find inverse of a given matrix
|
||||
>>> np.linalg.inv([[3,1],[2,4]])
|
||||
array([[ 0.4, -0.1],
|
||||
[-0.2, 0.3]])
|
||||
```
|
||||
|
||||
## Mathematics <a name="maths"></a>
|
||||
|
||||
### Operations <a name="ops"></a>
|
||||
| Operator | Description |Documentation|
|
||||
| :------------- | :------------- |:---------|
|
||||
|`np.add(x,y)`<br/>`x + y`|Addition|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.add.html)|
|
||||
|`np.substract(x,y)`<br/>`x - y`|Subtraction|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.subtract.html#numpy.subtract)|
|
||||
|`np.divide(x,y)`<br/>`x / y`|Division|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.divide.html#numpy.divide)|
|
||||
|`np.multiply(x,y)`<br/>`x @ y`|Multiplication|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.multiply.html#numpy.multiply)|
|
||||
|`np.sqrt(x)`|Square Root|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.sqrt.html#numpy.sqrt)|
|
||||
|`np.sin(x)`|Element-wise sine|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.sin.html#numpy.sin)|
|
||||
|`np.cos(x)`|Element-wise cosine|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.cos.html#numpy.cos)|
|
||||
|`np.log(x)`|Element-wise natural log|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.log.html#numpy.log)|
|
||||
|`np.dot(x,y)`|Dot product|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.dot.html)|
|
||||
|`np.roots([1,0,-4])`|Roots of a given polynomial coefficients|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.roots.html)|
|
||||
|
||||
Remember: NumPy array operations work element-wise.
|
||||
|
||||
#### Example <a name="operations-examples"></a>
|
||||
```python
|
||||
# If a 1d array is added to a 2d array (or the other way), NumPy
|
||||
# chooses the array with smaller dimension and adds it to the one
|
||||
# with bigger dimension
|
||||
a = np.array([1, 2, 3])
|
||||
b = np.array([(1, 2, 3), (4, 5, 6)])
|
||||
print(np.add(a, b))
|
||||
>>> [[2 4 6]
|
||||
[5 7 9]]
|
||||
|
||||
# Example of np.roots
|
||||
# Consider a polynomial function (x-1)^2 = x^2 - 2*x + 1
|
||||
# Whose roots are 1,1
|
||||
>>> np.roots([1,-2,1])
|
||||
array([1., 1.])
|
||||
# Similarly x^2 - 4 = 0 has roots as x=±2
|
||||
>>> np.roots([1,0,-4])
|
||||
array([-2., 2.])
|
||||
```
|
||||
|
||||
### Comparison
|
||||
| Operator | Description | Documentation |
|
||||
| :------------- | :------------- |:---------|
|
||||
|`==`|Equal|[link](https://docs.python.org/2/library/stdtypes.html)|
|
||||
|`!=`|Not equal|[link](https://docs.python.org/2/library/stdtypes.html)|
|
||||
|`<`|Smaller than|[link](https://docs.python.org/2/library/stdtypes.html)|
|
||||
|`>`|Greater than|[link](https://docs.python.org/2/library/stdtypes.html)|
|
||||
|`<=`|Smaller than or equal|[link](https://docs.python.org/2/library/stdtypes.html)|
|
||||
|`>=`|Greater than or equal|[link](https://docs.python.org/2/library/stdtypes.html)|
|
||||
|`np.array_equal(x,y)`|Array-wise comparison|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.array_equal.html)|
|
||||
|
||||
#### Example <a name="comparison-example"></a>
|
||||
```python
|
||||
# Using comparison operators will create boolean NumPy arrays
|
||||
z = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
|
||||
c = z < 6
|
||||
print(c)
|
||||
>>> [ True True True True True False False False False False]
|
||||
```
|
||||
### Basic Statistics <a name="stats"></a>
|
||||
| Operator | Description | Documentation |
|
||||
| :------------- | :------------- |:--------- |
|
||||
|`np.mean(array)`|Mean|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.mean.html#numpy.mean)|
|
||||
|`np.median(array)`|Median|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.median.html#numpy.median)|
|
||||
|`array.corrcoef()`|Correlation Coefficient|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.corrcoef.html#numpy.corrcoef)|
|
||||
|`np.std(array)`|Standard Deviation|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.std.html#numpy.std)|
|
||||
|
||||
#### Example <a name="stats-examples"></a>
|
||||
```python
|
||||
# Statistics of an array
|
||||
a = np.array([1, 1, 2, 5, 8, 10, 11, 12])
|
||||
|
||||
# Standard deviation
|
||||
print(np.std(a))
|
||||
>>> 4.2938910093294167
|
||||
|
||||
# Median
|
||||
print(np.median(a))
|
||||
>>> 6.5
|
||||
```
|
||||
|
||||
|
||||
### More <a name="more"></a>
|
||||
| Operator | Description | Documentation |
|
||||
| :------------- | :------------- |:--------- |
|
||||
|`array.sum()`|Array-wise sum|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.sum.html)|
|
||||
|`array.min()`|Array-wise minimum value|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.min.html)|
|
||||
|`array.max(axis=0)`|Maximum value of specified axis||
|
||||
|`array.cumsum(axis=0)`|Cumulative sum of specified axis|[link](https://docs.scipy.org/doc/numpy/reference/generated/numpy.cumsum.html)|
|
||||
|
||||
</br>
|
||||
|
||||
## Slicing and Subsetting <a name="ss"></a>
|
||||
|Operator|Description|Documentation|
|
||||
| :------------- | :------------- | :------------- |
|
||||
|`array[i]`|1d array at index i|[link](https://docs.scipy.org/doc/numpy/reference/arrays.indexing.html)|
|
||||
|`array[i,j]`|2d array at index[i][j]|see above|
|
||||
|`array[i<4]`|Boolean Indexing, see [Tricks](#tricks)|see above|
|
||||
|`array[0:3]`|Select items of index 0, 1 and 2|see above|
|
||||
|`array[0:2,1]`|Select items of rows 0 and 1 at column 1|see above|
|
||||
|`array[:1]`|Select items of row 0 (equals array[0:1, :])|see above|
|
||||
|`array[1:2, :]`|Select items of row 1|see above|
|
||||
[comment]: <> (|`array[1,...]`|equals array[1,:,:]|see above|)
|
||||
|`array[ : :-1]`|Reverses `array`|see above|
|
||||
|
||||
|
||||
#### Examples <a name="exp"></a>
|
||||
```python
|
||||
b = np.array([(1, 2, 3), (4, 5, 6)])
|
||||
|
||||
# The index *before* the comma refers to *rows*,
|
||||
# the index *after* the comma refers to *columns*
|
||||
print(b[0:1, 2])
|
||||
>>> [3]
|
||||
|
||||
print(b[:len(b), 2])
|
||||
>>> [3 6]
|
||||
|
||||
print(b[0, :])
|
||||
>>> [1 2 3]
|
||||
|
||||
print(b[0, 2:])
|
||||
>>> [3]
|
||||
|
||||
print(b[:, 0])
|
||||
>>> [1 4]
|
||||
|
||||
c = np.array([(1, 2, 3), (4, 5, 6)])
|
||||
d = c[1:2, 0:2]
|
||||
print(d)
|
||||
>>> [[4 5]]
|
||||
|
||||
```
|
||||
|
||||
</br>
|
||||
|
||||
## Tricks <a name="tricks"></a>
|
||||
This is a growing list of examples. Know a good trick? Let me know in a issue or fork it and create a pull request.
|
||||
|
||||
*boolean indexing*
|
||||
```python
|
||||
# Index trick when working with two np-arrays
|
||||
a = np.array([1,2,3,6,1,4,1])
|
||||
b = np.array([5,6,7,8,3,1,2])
|
||||
|
||||
# Only saves a at index where b == 1
|
||||
other_a = a[b == 1]
|
||||
#Saves every spot in a except at index where b != 1
|
||||
other_other_a = a[b != 1]
|
||||
```
|
||||
|
||||
```python
|
||||
import numpy as np
|
||||
x = np.array([4,6,8,1,2,6,9])
|
||||
y = x > 5
|
||||
print(x[y])
|
||||
>>> [6 8 6 9]
|
||||
|
||||
# Even shorter
|
||||
x = np.array([1, 2, 3, 4, 4, 35, 212, 5, 5, 6])
|
||||
print(x[x < 5])
|
||||
>>> [1 2 3 4 4]
|
||||
|
||||
```
|
||||
|
||||
</br>
|
||||
@@ -21,6 +21,7 @@ cat /proc/<process_id>/maps # Show the current virtual memory usage of a Linux
|
||||
ip r # Display ip of the server
|
||||
|
||||
lsof -i :9000 # List process running on port 9000
|
||||
kill -9 $(lsof -t -i:PORT) # Kill the process running on whichever port specified
|
||||
|
||||
journalctl -u minio.service -n 100 --no-pager # List last 100 logs for specific service
|
||||
|
||||
|
||||
@@ -20,13 +20,15 @@ e jump to end of words (punctuation considered words)
|
||||
E jump to end of words (no punctuation)
|
||||
b jump backward by words (punctuation considered words)
|
||||
B jump backward by words (no punctuation)
|
||||
ge jump backward to end of words
|
||||
ge jump backward to end of a word
|
||||
gE jump backwards to the end of a word (words can contain punctuation)
|
||||
0 (zero) start of line
|
||||
^ first non-blank character of line
|
||||
$ end of line
|
||||
- move line upwards, on the first non blank character
|
||||
+ move line downwards, on the first non blank character
|
||||
<enter> move line downwards, on the first non blank character
|
||||
$ jump to the end of the line
|
||||
g_ jump to the last non-blank character of the line
|
||||
- move line upwards, on the first non-blank character
|
||||
+ move line downwards, on the first non-blank character
|
||||
<enter> move line downwards, on the first non-blank character
|
||||
gg go to first line
|
||||
G go to last line
|
||||
ngg go to line n
|
||||
@@ -38,10 +40,6 @@ nG go To line n
|
||||
} move the cursor a paragraph forwards
|
||||
]] move the cursor a section forwards or to the next {
|
||||
[[ move the cursor a section backwards or the previous {
|
||||
CTRL-f move the cursor forward by a screen of text
|
||||
CTRL-b move the cursor backward by a screen of text
|
||||
CTRL-u move the cursor up by half a screen
|
||||
CTRL-d move the cursor down by half a screen
|
||||
H move the cursor to the top of the screen.
|
||||
M move the cursor to the middle of the screen.
|
||||
L move the cursor to the bottom of the screen.
|
||||
@@ -49,6 +47,16 @@ fx search line forward for 'x'
|
||||
Fx search line backward for 'x'
|
||||
tx search line forward before 'x'
|
||||
Tx search line backward before 'x'
|
||||
CTRL-y moves screen up one line
|
||||
CTRL-e moves screen down one line
|
||||
CTRL-u moves cursor & screen up ½ page
|
||||
CTRL-d moves cursor & screen down ½ page
|
||||
CTRL-b moves screen up one page, cursor to last line
|
||||
CTRL-f moves screen down one page, cursor to first line
|
||||
zz shift current line to middle of screen
|
||||
z. same as zz but also jumps to the first non-black character
|
||||
zt shift current line to top of screen
|
||||
zb shift current line to bottom of screen
|
||||
|
||||
|
||||
##############################################################################
|
||||
@@ -60,8 +68,15 @@ Tx search line backward before 'x'
|
||||
ma make a bookmark named a at the current cursor position
|
||||
`a go to position of bookmark a
|
||||
'a go to the line with bookmark a
|
||||
`0 go to the position where Vim was previously exited
|
||||
`" go to the position when last editing this file
|
||||
`. go to the line that you last edited
|
||||
`` go to the position before the last jump
|
||||
g, go to newer position in change list
|
||||
g; go to older position in change list
|
||||
|
||||
# Tip: To jump to a mark you can either use a backtick (`) or an apostrophe (').
|
||||
# Using an apostrophe jumps to the beginning (first non-blank) of the line holding the mark.
|
||||
|
||||
##############################################################################
|
||||
# INSERT MODE
|
||||
@@ -70,10 +85,13 @@ ma make a bookmark named a at the current cursor position
|
||||
|
||||
i start insert mode at cursor
|
||||
I insert at the beginning of the line
|
||||
gi return to insert mode where you inserted text the last time
|
||||
gI like "I", but always start in column 1
|
||||
a append after the cursor
|
||||
A append at the end of the line
|
||||
o open (append) blank line below current line
|
||||
O open blank line above current line
|
||||
CTRL-o Temporarily enter normal mode to issue one normal-mode command(while in insert mode)
|
||||
Esc exit insert mode
|
||||
|
||||
|
||||
@@ -84,10 +102,25 @@ Esc exit insert mode
|
||||
|
||||
r replace a single character (does not use insert mode)
|
||||
R enter Insert mode, replacing characters rather than inserting
|
||||
J join line below to the current one
|
||||
J join line below to the current one with one space in between
|
||||
gJ join line below to the current one without space in between
|
||||
cc change (replace) an entire line
|
||||
cw change (replace) to the end of word
|
||||
C change (replace) to the end of line
|
||||
cw change (replace) to the end of word (same as ce)
|
||||
2cw change (replace) repeat cw twice
|
||||
ciw change (replace) word under the cursor
|
||||
caw change (replace) word under the cursor and the space after or before it
|
||||
ci" change (replace) word inside ""
|
||||
cit change (replace) html tag content
|
||||
cat change (replace) html tag
|
||||
cis change (replace) sentence under the cursor
|
||||
cas change (replace) sentence under the cursor and the space after or before it
|
||||
cib change (replace) inside a block with ()
|
||||
cab change (replace) a block with ()
|
||||
ciB change (replace) inside a block with {}
|
||||
caB change (replace) a block with {}
|
||||
C change (replace) to the end of line(same as c$)
|
||||
cG change (replace) to the end of the file
|
||||
cgg change (replace) from first line to current line
|
||||
ct' change (replace) until the ' character (can change ' for any character)
|
||||
s delete character at cursor and substitute text
|
||||
S delete line at cursor and substitute text (same as cc)
|
||||
@@ -102,6 +135,7 @@ guiw make current word lowercase
|
||||
gU$ make uppercase until end of line
|
||||
gu$ make lowercase until end of line
|
||||
>> indent line one column to right
|
||||
>i{ indent everything in the {}
|
||||
<< indent line one column to left
|
||||
== auto-indent current line
|
||||
ddp swap current line with next
|
||||
@@ -110,6 +144,7 @@ ddkP swap current line with previous
|
||||
:r [name] insert the file [name] below the cursor.
|
||||
:r !{cmd} execute {cmd} and insert its standard output below the cursor.
|
||||
|
||||
# Tip: Instead of b or B one can also use ( or { respectively.
|
||||
|
||||
##############################################################################
|
||||
# DELETING TEXT
|
||||
@@ -118,10 +153,15 @@ ddkP swap current line with previous
|
||||
|
||||
x delete current character
|
||||
X delete previous character
|
||||
dw delete the current word
|
||||
dw delete (cut) to the end of word (same as de)
|
||||
diw delete (cut) word under the cursor
|
||||
daw delete (cut) word under the cursor and the space after or before it
|
||||
dap delete (cut) a paragraph
|
||||
dd delete (cut) a line
|
||||
dt' delete until the next ' character on the line (replace ' by any character)
|
||||
D delete from cursor to end of line
|
||||
dt' delete (cut) until the next ' character on the line (replace ' by any character)
|
||||
dG delete (cut) to the end of the file
|
||||
dgg delete (cut) from first line to current line
|
||||
D delete (cut) from cursor to end of line (same as d$)
|
||||
:[range]d delete [range] lines
|
||||
|
||||
|
||||
@@ -136,6 +176,10 @@ yy yank (copy) a line
|
||||
y$ yank to end of line
|
||||
p put (paste) the clipboard after cursor/current line
|
||||
P put (paste) before cursor/current line
|
||||
gp put (paste) the clipboard after cursor and leave cursor after the new text
|
||||
gP put (paste) before cursor and leave cursor after the new text
|
||||
"+y yank into the system clipboard register
|
||||
"+p paste from the system clipboard register
|
||||
:set paste avoid unexpected effects in pasting
|
||||
:registers display the contents of all registers
|
||||
"xyw yank word into register x
|
||||
@@ -147,6 +191,12 @@ P put (paste) before cursor/current line
|
||||
"xgP just like "P", but leave the cursor just after the new text
|
||||
:[line]put x put the text from register x after [line]
|
||||
|
||||
# Tip: if you are using vim extension on vs code, you can enable
|
||||
"vim.useSystemClipboard": true
|
||||
in setting.json, this will allow to Use system clipboard for unnamed register.
|
||||
|
||||
|
||||
|
||||
|
||||
##############################################################################
|
||||
# MACROS
|
||||
@@ -157,6 +207,7 @@ qa start recording macro 'a'
|
||||
q end recording macro
|
||||
@a replay macro 'a'
|
||||
@: replay last command
|
||||
@@ repeat macro
|
||||
|
||||
|
||||
##############################################################################
|
||||
@@ -172,9 +223,11 @@ CTRL-v start visual block mode
|
||||
O move to other corner of block
|
||||
aw mark a word
|
||||
ab a () block (with braces)
|
||||
ab a {} block (with brackets)
|
||||
aB a {} block (with brackets)
|
||||
at a block with <> tags
|
||||
ib inner () block
|
||||
ib inner {} block
|
||||
iB inner {} block
|
||||
it inner <> block
|
||||
Esc exit visual mode
|
||||
|
||||
VISUAL MODE COMMANDS
|
||||
@@ -194,6 +247,7 @@ v% selects matching parenthesis
|
||||
vi{ selects matching curly brace
|
||||
vi" selects text between double quotes
|
||||
vi' selects text between single quotes
|
||||
gv reselect the last selected area
|
||||
|
||||
##############################################################################
|
||||
# SPELLING
|
||||
@@ -283,7 +337,6 @@ CTRL-w < increase window width
|
||||
CTRL-w > decrease window width
|
||||
CTRL-w = equal window
|
||||
CTRL-w o close other windows
|
||||
zz Centers the window to the current line
|
||||
|
||||
|
||||
##############################################################################
|
||||
@@ -306,12 +359,14 @@ clast display the last error
|
||||
|
||||
|
||||
% show matching brace, bracket, or parenthese
|
||||
gf edit the file whose name is under or after the cursor
|
||||
gf edit the file whose name is under the cursor
|
||||
gF edit the file whose name is under the cursor and jump to the line number
|
||||
gd when the cursor is on a local variable or function, jump to its declaration
|
||||
'' return to the line where the cursor was before the latest jump
|
||||
gi return to insert mode where you inserted text the last time
|
||||
CTRL-o move to previous position you were at
|
||||
CTRL-i move to more recent position you were at
|
||||
:set nu display numbers (short for :set number)
|
||||
:set nonu hide numbers (short for :set nonumber)
|
||||
|
||||
|
||||
##############################################################################
|
||||
|
||||
Reference in New Issue
Block a user