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Python Cheat Sheet

Print statement
print("Hello, world!")
Outputs the given text to the console
# This is a comment
Comments are ignored by Python and are used to document code
Multiline comment
This is a multiline comment.
It can span multiple lines without the need for multiple comment symbols.
You can use it to document your code or temporarily disable a block of code.
x = 5
Variables are used to store data and can be assigned and reassigned values
Data types
int, float, string, bool, list, tuple, dict, set
Different types of data that can be stored in variables
Numeric operations
+, -, *, /, %, **
Operators used for arithmetic operations
Comparison operators
==, !=, >, <, >=, <=
Operators used to compare values
Logical operators
and, or, not
Operators used to combine and manipulate boolean values
Conditional statements
if, elif, else
Statements used to conditionally execute code
for, while
Statements used to iterate over a sequence of data
def my_func():, return
Blocks of code that can be called and returned
Lambda functions
lambda x: x + 1
Anonymous functions used for simple operations
class MyClass:, def init(self):, self
Used to define custom data types and associated functions
List methods
append(), extend(), insert(), remove(), pop(), index(), count(), sort(), reverse()
Methods used to manipulate lists
Tuple methods
count(), index()
Methods used to manipulate tuples
Dictionary methods
keys(), values(), items(), get(), update(), pop(), popitem(), clear()
Methods used to manipulate dictionaries
Set methods
add(), remove(), discard(), pop(), clear(), union(), intersection(), difference(), symmetric_difference()
Methods used to manipulate sets

Getting Started

  • Corey Schafer, Object-Oriented Programming 6 parts
  • Setting up a Python Development Environment
    • Requirements: syntax highlighting, beautification, linter, IntelliSense: list members, parameter info, quick info, autocompletion,


  • Why? Logically group our data and functions that we can easily reuse or build upon
  • Terminology
    • Attributes and methods - functions that is associated with class
    • A class is a blueprint for creating instances
class Employee:
# instances of a Employee classes
emp_1 = Employee()
emp_2 = Employee()
# unique data
#manually variable setting - prone to human error
emp_1.first = 'Corey'
emp_1.last = 'Scafer' = '[email protected]' = '50000'
emp_2.first = 'Test'
emp_2.last = 'User' = '[email protected]' = '60000'
class Employee:
def __init__(self,first,last,pay):
#set instance variable
self.first = first
self.last = last =pay = first +'.' + last + ''
# each method within a class automatically takes the insance as the first argument
# and we always call that self
def fullname(self)
return '{}{}'.format(self.first,self.last)
# better solution: runs init automatically
emp_1 = Employee('Corey','Scafer',50000)
emp_2 = Employee('Test','User',60000)
# running actions
# better
print(emp_1.fullname()) # notice the parenthesis as it is a method
#classes are kinda like function
# remember to put self in methods in class
emp_1.fullname() is same as Employee.fullname(emp_1))