python lambda function

Reference URL: http://www.runoob.com/python/python-tutorial.html

lambda function: need a function, but don't want to define a function, so use lambda anonymous function

Takes any number of arguments (including optional arguments) and returns the value of a single expression.

Example 1: lambda function passing in 1 parameter

a = lambda x:x*x
print(a(3))

Example 2: A lambda function with 2 arguments
def sum(x,y):
return x+y
is implemented as a lambda:
a = lambda x,y:x+y
print(a(4,6)) 

Example 3: lambda form with multiple parameters:

a = lambda x, y, z: (x + 8) * yz

print(a(5,6,8))

Example 4: lambda vs. directly defining function

map( lambda x: x*x, [y for y in range(10)] )

This way of writing is better than:

def sq(x):
    return x * x

map(sq, [y for y in range(10)])