how to use def in python

1#Letters, Nums,
2#& underscores
3#only, can't	=7  
4#start w/ num	|		  _ 5 is the default value if no
5# 	  |			|		 |  value is passed
6#	  v         v        v
7def funcName(param1, param2=5): #The colon terminates func header 
8	str(param1) #Typecasting is temparary
9    strVar = str(param1) # To make typecast perma, assign to var
10    param1 = param2 # 5 is passed to param1 
11    return param1 # 5 is returned
12#	  ^      ^
13#     |		 |_ return value is optional, if no return value, func 
14  #Optional		will end returning to func call
15  #return
16
17x = funcName(7)
18print(x) # prints 5

1# declare a function
2def function_name(param) :
3  # content inside a function
4
5function_name(param) # calling function

1
2  def my_function():
3  print("Hello from a function")
4
5
6  my_function() 

1# You can make a function by using the [def] keyword
2def foo():
3	print("Hello")
4
5# You can run it by calling it as such
6foo()
7
8def add(numA, numB):
9  print(numA+numB)
10  # or 
11  return numA+numB
12
13num = add(1, 5)
14print(num)

1def function():
2  print('This is a basic function')
3  
4function()
5// Returns 'This is a basic function'
6
7def add(numA, numB):
8  print(numA+numB)
9  
10add(1,2)
11// Returns 3
12
13def define(value):
14  return value
15
16example = define('Lorem ipsum')
17print(example)
18// Returns 'Lorem ipsum'
19
20

1def firstProgram(x):
2    print(x)
3
4firstProgram("Hello, World!")
5# Prints "Hello, World!"