Python Cheat Sheet

Table of Contents

1. Variables and Data Types
2. Control Structures
3. Functions
4. Lists and Dictionaries
5. File Handling

1. Variables and Data Types

Creating variables

name = "John"     # creates a variable 'name' with the value "John"
age = 25          # creates a variable 'age' with the value 25
height = 1.75     # creates a variable 'height' with the value 1.75
is_student = True # creates a variable 'is_student' with the value True

Data types

string = "Hello, World!" # creates a string variable
integer = 42            # creates an integer variable
float = 3.14            # creates a float variable
boolean = True          # creates a boolean variable

2. Control Structures

If statement

if x > 0:
    print("x is positive")
elif x == 0:
    print("x is zero")
else:
    print("x is negative")

For loop

for i in range(10):
    print(i)

While loop

while x < 10:
    print(x)
    x += 1

3. Functions

Defining a function

def greet(name):
    print("Hello, " + name + "!")

Calling a function

greet("John")

4. Lists and Dictionaries

Creating a list

fruits = ["apple", "banana", "cherry"]

Accessing list elements

print(fruits[0])   # prints "apple"
print(fruits[-1])  # prints "cherry"

Adding elements to a list

fruits.append("orange")
fruits.insert(1, "pear")

Creating a dictionary

person = {"name": "John", "age": 25, "is_student": True}

Accessing dictionary elements

print(person["name"])    # prints "John"
print(person.get("age")) # prints 25

Adding elements to a dictionary

person["height"] = 1.75
person.update({"weight": 70})

5. File Handling

Reading from a file

with open("file.txt", "r") as f:
    contents = f.read()

This is a cheat sheet for Python that covers the most commonly used syntax and concepts. You can use this cheat sheet as a quick reference guide when working with Python.