Python Function Syntax

You can read about what functions are here.

Here are some examples of simple functions:

def f(x):
    return x+2

def g(y):
    return y*5

def h(a, b):
    result = a + b
    return result

Here's how to call the functions:

result1 = f(123)
result2 = g(10)
result3 = h(5, 7)

Here are all the parts that go into a function:

• the def keyword
  • this tells Python we're defining a function
• the function name
  • it must obey the same rules as for variable names
  • use all-lowercase with underscores for spaces
• a left parenthesis (
• one or more parameters
  • these are similar to variables
  • the parameters take the values of the function call arguments
  • multiple parameters, if any, are separated by commas
• a right parenthesis )
• a colon :
• the function body
  • this is the code that runs when you call the function
  • the function body must be indented (moved four spaces in)
• the return keyword
  • this goes inside the function body
  • it sends a value back to the caller of the function

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