A couple ways to use map() when you need nested function calls.

lambda_map.py

# Core functions
def triple(num):
  return num*3

def double(num):
	return num*2

# Input values
nums = [1,2,3,4,5,6]


# With lambda
def use_lambda():
	print map(lambda x: triple(double(x)), nums)


# With an itermediate "composite" function
def composite_function(num):
	return triple(double(num))

def use_composite_function():
	print map(composite_function, nums)

# Entry point compares both valid ways of using map()
if __name__ == '__main__':
	use_lambda()
	use_composite_function()