Python Syntax Guide

Key Concepts

• Value (data types)
  • String
    • Text value
  • Int
    • Number value (no decimal places)
  • Float
    • Number value (has decimal places)
  • Boolean
    • True or false value
• Variable
  • Used to store values
  • Has a unique name that you choose
• Operator
  • Used for assigning a value to a variable
  • Used for math between two values or variables
• Function
  • Pre-written code that can be used repeatedly
• Print
  • Function that displays a string in the console
• Error
  • Text displayed in the console when Python detects a mistake
  • Shows the location (line number) of the mistake
• Statement
  • A single line of code that does something
  • Like a sentence, every statement has a subject and a verb
• Comment
  • Not interpreted by Python
  • Used to explain what the code does
• Console
  • Where you see the program’s output (print results and errors)

Syntax

• Values
  • Use quotation marks (" or ') around a string
  • Use decimal points (.) to turn an int into a float
  • Booleans can only be True or False
• Functions
  • Use parentheses (()) after the name to use a function
  • Add the parameter between the parentheses if needed (like in print)
• Comments
  • Use an octothorpe (#) to start a single-line comment
  • Use triple quotes (""") around a multi-line comment
• Some common operators
  • A = B
    • Set variable A to the value of B
  • A + B
    • Add A and B
  • A - B
    • Subtract B from A
  • A * B
    • Multiply A by B
  • A / B
    • Divide A by B

Code Snippets / Examples

"""
Use comments to describe your code.
Each single line below is a statement.
"""

# values and variables
string_variable = "hello world"
int_variable = 1
float_variable = 1.5
boolean_variable = True

# operators
math_problem = (int_variable + float_variable) / 3

# functions
print(string_variable) # hello world