Python Lambda Functions: Syntax and Examples
Learn about lambda functions in Python, which are small, anonymous functions defined using the lambda
keyword. Discover the syntax and see how lambda functions can take multiple arguments and return a single expression as a result. Explore practical examples, including how to add values using lambda functions.
Python Lambda Functions
A lambda function in Python is a small, anonymous function defined using the lambda
keyword. It can take any number of arguments but only has a single expression.
Syntax
lambda arguments: expression
The expression is evaluated and returned as the result.
Example 1: Add 10 to the argument a
Example
x = lambda a: a + 10
print(x(15))
Output
25
Example 2: Multiply arguments a
and b
Example
x = lambda a, b: a * b
print(x(7, 8))
Output
56
Example 3: Sum arguments a
, b
, and c
Example
x = lambda a, b, c: a + b + c
print(x(3, 4, 5))
Output
12
Why Use Lambda Functions?
Lambda functions are particularly useful when used as anonymous functions inside other functions. For instance, you might have a function that multiplies its argument by an unknown number:
Example
def myfunc(n):
return lambda a: a * n
# Function to double the input
mydoubler = myfunc(2)
print(mydoubler(10))
Output
20
You can also create a function that triples the input:
Example
def myfunc(n):
return lambda a: a * n
# Function to triple the input
mytripler = myfunc(3)
print(mytripler(10))
Output
30
Combining both in a single program:
Example
def myfunc(n):
return lambda a: a * n
mydoubler = myfunc(2)
mytripler = myfunc(3)
print(mydoubler(10))
print(mytripler(10))
Output
20
30