From 1643b90b9e1ead701a93759b4d98f159b04cb5a0 Mon Sep 17 00:00:00 2001 From: Alkkem <72548193+Alkkem@users.noreply.github.com> Date: Thu, 3 Dec 2020 16:28:56 +0100 Subject: [PATCH 1/4] Added more shortcuts to the "ALT" section Added shortcuts to the ALT section, in particular those that come after "ALT+H" --- languages/bash.sh | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/languages/bash.sh b/languages/bash.sh index d864fb5..df781ee 100644 --- a/languages/bash.sh +++ b/languages/bash.sh @@ -32,6 +32,12 @@ ALT+B # moves backward one word ALT+D # deletes next word ALT+F # moves forward one word ALT+H # deletes one character backward +ALT+T # transposes two words +ALT+. # pastes last word from the last command. Pressing it repeatedly traverses through command history. +ALT+U # capitalizes every character from the current cursor position to the end of the word +ALT+L # uncapitalizes every character from the current cursor position to the end of the word +ALT+C # capitalizes the letter under the cursor. The cursor then moves to the end of the word. +ALT+R # reverts any changes to a command you’ve pulled from your history if you’ve edited it. BACKSPACE # deletes one character backward DELETE # deletes one character under cursor From f59ffcfa93729d6b392ec20712ad0cd42c6e1a2d Mon Sep 17 00:00:00 2001 From: Matthew Hiebing Date: Sun, 6 Dec 2020 20:22:45 -0600 Subject: [PATCH 2/4] Grammatical Error under Visual Studio Cheatsheet > Git Small grammatical error under VSC > Git. Changed, "- [`Gitignore`](https://marketplace.visualstudio.com/items?itemName=codezombiech.gitignore): A extension for Visual Studio Code that assists you in working with .gitignore files." to: "- [`Gitignore`](https://marketplace.visualstudio.com/items?itemName=codezombiech.gitignore): An extension for Visual Studio Code that assists you in working with .gitignore files." --- tools/vscode.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/vscode.md b/tools/vscode.md index b46d3eb..51cecec 100644 --- a/tools/vscode.md +++ b/tools/vscode.md @@ -44,7 +44,7 @@ - [`Git History`](https://marketplace.visualstudio.com/items?itemName=donjayamanne.githistory): View git log, file history, compare branches or commits. -- [`Gitignore`](https://marketplace.visualstudio.com/items?itemName=codezombiech.gitignore): A extension for Visual Studio Code that assists you in working with .gitignore files. +- [`Gitignore`](https://marketplace.visualstudio.com/items?itemName=codezombiech.gitignore): An extension for Visual Studio Code that assists you in working with .gitignore files. ### Themes From d590c82ecb8f9db29ede37d8035ab121405838de Mon Sep 17 00:00:00 2001 From: Jay <47923507+jveer634@users.noreply.github.com> Date: Tue, 8 Dec 2020 00:36:18 +0530 Subject: [PATCH 3/4] Added python cheat sheet to the languages folder. I intentionally skipped the OOPS concept as it consists more data which is making cheat book but not sheet, Please do mention if I'm missing, I will add them. --- languages/python.md | 321 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 languages/python.md diff --git a/languages/python.md b/languages/python.md new file mode 100644 index 0000000..af85c48 --- /dev/null +++ b/languages/python.md @@ -0,0 +1,321 @@ +# Python + +* Python is an interpreted, high-level and general-purpose, dynamically typed programming language + +* It is also Object oriented, modular oriented and a scripting language. + +* In Python, everything is considered as an Object. + +* A python file has an extension of .py + +* Python follows Indentation to separate code blocks instead of flower brackets({}). + +* We can run a python file by the following command in cmd(Windows) or shell(mac/linux). + + `python ` + +#### By default, the python doesn't require any imports to run a python file. + +## Create and execute a program + +1. Open up a terminal/cmd +1. Create the program: nano/cat > nameProgram.py +1. Write the program and save it +1. python nameProgram.py + +
+ +### Basic Datatypes + +| Data Type | Description | +| --------- | ----------- | +| int | Integer values [0, 1, -2, 3] | +| float | Floating point values [0.1, 4.532, -5.092] | +| char | Characters [a, b, @, !, `] | +| str | Strings [abc, AbC, A@B, sd!, `asa] | +| bool | Boolean Values [True, False] | +| char | Characters [a, b, @, !, `] | +| complex | Complex numbers [2+3j, 4-1j] | + +
+ +## Keywords +
+ +| Keyword | Description | +| --------- | ----------- | +| break | used to exit loop and used to exit| +| char | basic declaration of a type character | +| const | prefix declaration meaning variable can not be changed| +| continue | go to bottom of loop in for, while loops| +| class | to define a class| +| def | to define a function| +| elif | shortcut for (else if) used in else if ladder | +| else | executable statement, part of "if" structure | +| float | basic declaration of floating point| +| for | executable statement, for loop| +| from | executable statement, used to import only specific objects from a package| +| if | executable statement| +| import | to import modules| +|pass| keyword to specify noting is happening in the codeblock, generally used in classes| +|return | executable statement with or without a value| +|while| executable statement, while loop| +
+ +## Operators + +
+ +| Operator | Description | +|-|-| +| ( ) | grouping parenthesis, function call, tuple declaration | +| [ ] | array indexing, also declaring lists etc.| +| ! | relational not, complement, ! a yields true or false | +| ~ | bitwise not, ones complement, ~a | +| \- | unary minus, - a | +| \+ | unary plus, + a | +| \* | multiply, a * b | +| / | divide, a / b | +| % | modulo, a % b | +| \+ | add, a + b | +| \- | subtract, a - b | +| << | shift left, left operand is shifted left by right operand bits | +| \>> | shift right, left operand is shifted right by right operand bits| + | < | less than, result is true or false, a %lt; b +| <= | less than or equal, result is true or false, a <= b +| \> | greater than, result is true or false, a > b +| \>= | greater than or equal, result is true or false, a >= b +| == | equal, result is true or false, a == b +| != | not equal, result is true or false, a != b +| & | bitwise and, a & b +| ^ | bitwise exclusive or XOR, a ^ b +| \| | bitwise or, a | b +| &&, and | relational and, result is true or false, a < b && c >= d +| \|\|, or | relational or, result is true or false, a < b \|\| c >= d | +| = | store or assignment | +| += | add and store | +| -= | subtract and store | +| *= | multiply and store | +| /= | divide and store| +| %= | modulo and store| +| <<= | shift left and store| +| \>>= | shift right and store| +| &= | bitwise and and store| +| ^= | bitwise exclusive or and store| +| \|= | bitwise or and store| +| , | separator as in ( y=x,z=++x )| + +### Basic Data Structures + +### List + +- List is a collection which is ordered and changeable. Allows duplicate members. + + +- Lists are created using square brackets: + +```py +thislist = ["apple", "banana", "cherry"] +``` + +- List items are ordered, changeable, and allow duplicate values. + +- List items are indexed, the first item has index `[0]`, the second item has index `[1]` etc. + +- The list is changeable, meaning that we can change, add, and remove items in a list after it has been created. + +- To determine how many items a list has, use the `len()` function. + +- A list can contain different data types: +```py +list1 = ["abc", 34, True, 40, "male"] +``` +- It is also possible to use the list() constructor when creating a new list +```py +thislist = list(("apple", "banana", "cherry")) # note the double round-brackets +``` +### Tuple +- Tuple is a collection which is ordered and unchangeable. Allows duplicate members. +- A tuple is a collection which is ordered and unchangeable. +- Tuples are written with round brackets. +```py +thistuple = ("apple", "banana", "cherry") +``` +- Tuple items are ordered, unchangeable, and allow duplicate values. +- Tuple items are indexed, the first item has index `[0]`, the second item has index `[1]` etc. +- When we say that tuples are ordered, it means that the items have a defined order, and that order will not change. + +- Tuples are unchangeable, meaning that we cannot change, add or remove items after the tuple has been created. +- Since tuple are indexed, tuples can have items with the same value: +- Tuples allow duplicate values: +```py +thistuple = ("apple", "banana", "cherry", "apple", "cherry") +``` +- To determine how many items a tuple has, use the `len()`function: +```py +thistuple = ("apple", "banana", "cherry") +print(len(thistuple)) +``` +- To create a tuple with only one item, you have to add a comma after the item, otherwise Python will not recognize it as a tuple. +```py +thistuple = ("apple",) +print(type(thistuple)) + +#NOT a tuple +thistuple = ("apple") +print(type(thistuple)) +``` +- It is also possible to use the tuple() constructor to make a tuple. +```py + +thistuple = tuple(("apple", "banana", "cherry")) # note the double round-brackets +print(thistuple) +``` + +### Set +- Set is a collection which is unordered and unindexed. No duplicate members. +- A set is a collection which is both unordered and unindexed. +```py +thisset = {"apple", "banana", "cherry"} +``` +- Set items are unordered, unchangeable, and do not allow duplicate values. +- Unordered means that the items in a set do not have a defined order. + +- Set items can appear in a different order every time you use them, and cannot be referred to by index or key. + +- Sets are unchangeable, meaning that we cannot change the items after the set has been created. +- Duplicate values will be ignored. +- To determine how many items a set has, use the `len()` method. +```py +thisset = {"apple", "banana", "cherry"} + +print(len(thisset)) +``` +- Set items can be of any data type: +```py +set1 = {"apple", "banana", "cherry"} +set2 = {1, 5, 7, 9, 3} +set3 = {True, False, False} +set4 = {"abc", 34, True, 40, "male"} +``` +- It is also possible to use the `set()` constructor to make a set. +```py +thisset = set(("apple", "banana", "cherry")) # note the double round-brackets +``` +### Dictionary +- Dictionary is a collection which is unordered and changeable. No duplicate members. +- Dictionaries are used to store data values in key:value pairs. +- Dictionaries are written with curly brackets, and have keys and values: +```py +thisdict = { + "brand": "Ford", + "model": "Mustang", + "year": 1964 +} +``` +- Dictionary items are presented in key:value pairs, and can be referred to by using the key name. +```py +thisdict = { + "brand": "Ford", + "model": "Mustang", + "year": 1964 +} +print(thisdict["brand"]) +``` +- Dictionaries are changeable, meaning that we can change, add or remove items after the dictionary has been created. +- Dictionaries cannot have two items with the same key. +- Duplicate values will overwrite existing values. +- To determine how many items a dictionary has, use the `len()` function. +```py +print(len(thisdict)) +``` +- The values in dictionary items can be of any data type +```py +thisdict = { + "brand": "Ford", + "electric": False, + "year": 1964, + "colors": ["red", "white", "blue"] +} +``` + +### Conditional branching + +```py + if condition: + pass + elif condition2: + pass + else: + pass +``` +### Loops + + Python has two primitive loop commands: +1. while loops +2. for loops + +#### While loop +- With the `while` loop we can execute a set of statements as long as a condition is true. +- Example: Print i as long as i is less than 6 +```py +i = 1 +while i < 6: + print(i) + i += 1 +``` +- The while loop requires relevant variables to be ready, in this example we need to define an indexing variable, i, which we set to 1. +- With the `break` statement we can stop the loop even if the while condition is true +- With the continue statement we can stop the current iteration, and continue with the next. + +- With the else statement we can run a block of code once when the condition no longer is true. + +#### For loop +- A for loop is used for iterating over a sequence (that is either a list, a tuple, a dictionary, a set, or a string). + +- This is less like the for keyword in other programming languages, and works more like an iterator method as found in other object-orientated programming languages. + +- With the for loop we can execute a set of statements, once for each item in a list, tuple, set etc. +```py +fruits = ["apple", "banana", "cherry"] +for x in fruits: + print(x) +``` +- The for loop does not require an indexing variable to set beforehand. +- To loop through a set of code a specified number of times, we can use the range() function. +- The range() function returns a sequence of numbers, starting from 0 by default, and increments by 1 (by default), and ends at a specified number. +- The range() function defaults to increment the sequence by 1, however it is possible to specify the increment value by adding a third parameter: range(2, 30, 3). +- The else keyword in a for loop specifies a block of code to be executed when the loop is finished. +A nested loop is a loop inside a loop. + +- The "inner loop" will be executed one time for each iteration of the "outer loop": + +```py +adj = ["red", "big", "tasty"] +fruits = ["apple", "banana", "cherry"] + +for x in adj: + for y in fruits: + print(x, y) +``` +- for loops cannot be empty, but if you for some reason have a for loop with no content, put in the pass statement to avoid getting an error. + +```py +for x in [0, 1, 2]: + pass +``` + +### Function definition +```py +def function_name(): + return +``` +### Function call + +```py +function_name() +``` + +* We need not to specify the return type of the function. +* Functions by default return `None` +* We can return any datatype. From 2ab007e2a34df5009594a50f3a3a2c789374787d Mon Sep 17 00:00:00 2001 From: Jay <47923507+jveer634@users.noreply.github.com> Date: Sat, 12 Dec 2020 15:56:23 +0530 Subject: [PATCH 4/4] Added Python link to README --- README.md | 1 + 1 file changed, 1 insertion(+) diff --git a/README.md b/README.md index 73305aa..bfb8025 100644 --- a/README.md +++ b/README.md @@ -29,6 +29,7 @@ Feel free to take a look. You might learn new things. They have been designed to - [C#](languages/C%23.txt) - [PHP](languages/php.php) - [JAVA](languages/java.md) +- [Python](languages/python.md) #### Functional