Recursion and Lambda Functions in python.ppt

Recursion and Lambda Functions in python.ppt

• 1.
  RECURSION AND LAMBDAFUNCTIONS VINAY AGRAWAL ASST. PROFESSOR CEA DEPT. GLA UNIVERSITY, MATHURA
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  Recursion
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  Tower of HanoiProblem
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  def toh(source,destination,aux,n): if n>=1: toh(source,aux,destination,n-1) print("Move",source,"to",destination) toh(aux,destination,source,n-1) toh('A','B','C',3)
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  Programs 1. WAP tofind the factorial of a number provided by user using Recursion. 2. WAP to print the fibonacci Series upto n terms, where n is provided by user. 3. WAP to find the GCD (or HCF) using Recursion. 4. WAP to input a string from the user and check whether it is palindrome or not.
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  Lambda Functions orAnonymous Functions  Those Functions which does not have any name is called Anonymous Functions. In Python, this can be achieved by using keyword lambda, that’s why it is also called Lambda Functions.  They are not declared in the standard manner by using the def keyword  Lambda forms can take any number of arguments but return just one value in the form of an expression. They cannot contain commands or multiple expressions.
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  Syntax  The syntaxof lambda functions contains only a single statement, which is as follows: lambda arg1 ,arg2,.....argn:expression Example: add = lambda a, b : a + b print("Value of total : ", add( 10, 20 ) )
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  Non-Anonymous Function AnonymousFunction def square(x): return x*x n=int(input(“Enter the Number”)) print(square(n)) a=lambda x:x*x n=int(input(“Enter the Number”)) print(a(n))
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  Lambda Function withmap() function l=list(map(int,input().split())) Similarly L1=[1,2,3,4] L2=list(map(lambda x:x*x,L1)) print(L2) Output:[1,4,9,16]
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  Lambda Function withfilter() function L1=[1,2,3,4] L2=list(filter(lambda x:x%2==0,L1)) print(L2) Output:[2,4]
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  Lambda Function withreduce() function import functools L1=[1,2,3,4,5,6,7,8,9,10] L2=functools.reduce((lambda a , b : a+b), L1) print(L2) Output:55