❖ What are Python Lambda functions?
❖ Why are they used?
❖ How to write Anonymous functions?
❖ Lambda functions within user defined functions
• filter()
• map()
❖ Using Anonymous functions within
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• reduce()
❖Solving Algebraic expressions using Lambda
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PythonLambda Functionsare:
• Anonymousornameless functions
• ‘lambda’isnotaname,butitsakeyword
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Also known as throw-
away functions as they
are needed just once
They are also passed
as inputs or returned
as outputs of other
higher-order functions
The body of Lambda
functions is written in
a single line
One-time use I/O of other functions Reduce code size
Why are they used?
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A Lambda function is created using the lambda
operator
lambda arguments: expression
lambda : “Specify the purpose”
lambda a1…n: “Specify use of a1…n“
lambda a1: “Specify use of a1“
SYNTAX:
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Lambda functions are best used within other higher-
order functions
Anonymous functions within
user defined functions
def new_func(x):
return(lambda y: x+y)
t=new_func(3)
u=new_func(2)
print(t(3))
print(u(3))
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filter()
Used to filter the given iterables(lists, sets, etc) with the help
of another function passed as an argument to test all the
elements to be true or false.
my_list = [2,3,4,5,6,7,8]
new_list = list(filter(lambda a: (a/3 == 2), my_list))
print(new_list)
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map():
Applies a given function to all the iterables and returns a
new list.
my_list = [2,3,4,5,6,7,8]
new_list = list(map(lambda a: (a/3 != 2), li))
print(new_list)
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reduce():
Applies some other function to a list of elements that are
passed as a parameter to it and finally returns a single
value.
from functools import reduce
reduce(lambda a,b: a+b, [23,21,45,98])
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Copyright © 2017, edureka and/or its affiliates. All rights reserved.
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What is Python Lambda Function? Python Tutorial | Edureka

  • 2.
    ❖ What arePython Lambda functions? ❖ Why are they used? ❖ How to write Anonymous functions? ❖ Lambda functions within user defined functions • filter() • map() ❖ Using Anonymous functions within www.edureka.co/python • reduce() ❖Solving Algebraic expressions using Lambda
  • 3.
  • 4.
    www.edureka.co PythonLambda Functionsare: • Anonymousornamelessfunctions • ‘lambda’isnotaname,butitsakeyword www.edureka.co/python
  • 5.
  • 6.
    Also known asthrow- away functions as they are needed just once They are also passed as inputs or returned as outputs of other higher-order functions The body of Lambda functions is written in a single line One-time use I/O of other functions Reduce code size Why are they used? www.edureka.co/python
  • 7.
  • 8.
    A Lambda functionis created using the lambda operator lambda arguments: expression lambda : “Specify the purpose” lambda a1…n: “Specify use of a1…n“ lambda a1: “Specify use of a1“ SYNTAX: www.edureka.co/python
  • 9.
  • 10.
    Lambda functions arebest used within other higher- order functions Anonymous functions within user defined functions def new_func(x): return(lambda y: x+y) t=new_func(3) u=new_func(2) print(t(3)) print(u(3)) www.edureka.co/python
  • 11.
  • 12.
    filter() Used to filterthe given iterables(lists, sets, etc) with the help of another function passed as an argument to test all the elements to be true or false. my_list = [2,3,4,5,6,7,8] new_list = list(filter(lambda a: (a/3 == 2), my_list)) print(new_list) www.edureka.co/python
  • 13.
    map(): Applies a givenfunction to all the iterables and returns a new list. my_list = [2,3,4,5,6,7,8] new_list = list(map(lambda a: (a/3 != 2), li)) print(new_list) www.edureka.co/python
  • 14.
    reduce(): Applies some otherfunction to a list of elements that are passed as a parameter to it and finally returns a single value. from functools import reduce reduce(lambda a,b: a+b, [23,21,45,98]) www.edureka.co/python
  • 15.
  • 16.
    Copyright © 2017,edureka and/or its affiliates. All rights reserved. www.edureka.co
  • 17.