Lambda Functions

Tags: @lambda @functions

Lambda functions are small anonymous functions. They can take any number of arguments, but can only have one expression.

The general syntax is: lambda [arguments] : [expression]

# Example function - the normal way
def foo(x):
	return x + 10

# Equivalent lambda form
foo = lambda x : x + 10

# In both cases, function can be called by:
>>> foo(5)
>>> 15

# We can also do multiple arguments:
foo = lambda a, b, c : a + b + c

# This adds up a + b + c
>>> foo(1,2,3)
>>> 6

Use cases

You can use lambda functions inside other functions.

def foo(n):
	return lambda x : x * n

# Now you can do this to made a function that doubles the number
bar = foo(2)

# which will do
>>> bar(10)
>>> 20

# Or if you want a function to triple the number, do:
bar2 = foo(3)

# which does
>>> bar2(10)
>>> 30