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Python Math: Print all permutations of a given string

Python Math: Exercise-16 with Solution

Write a Python program to print all permutations of a given string (including duplicates).

In mathematics, the notion of permutation relates to the act of arranging all the members of a set into some sequence or order, or if the set is already ordered, rearranging (reordering) its elements, a process called permuting. These differ from combinations, which are selections of some members of a set where order is disregarded.

In the following image each of the six rows is a different permutation of three distinct balls

permutation of numbers

Sample Solution:-

Python Code:

def permute_string(str):
    if len(str) == 0:
        return ['']
    prev_list = permute_string(str[1:len(str)])
    next_list = []
    for i in range(0,len(prev_list)):
        for j in range(0,len(str)):
            new_str = prev_list[i][0:j]+str[0]+prev_list[i][j:len(str)-1]
            if new_str not in next_list:
                next_list.append(new_str)
    return next_list

print(permute_string('ABCD'));

Sample Output:

['ABCD', 'BACD', 'BCAD', 'BCDA', 'ACBD', 'CABD', 'CBAD', 'CBDA', 'ACDB', 'CADB', 'CDAB', 'CDBA', 'ABDC', 'BADC
', 'BDAC', 'BDCA', 'ADBC', 'DABC', 'DBAC', 'DBCA', 'ADCB', 'DACB', 'DCAB', 'DCBA'] 

Flowchart:

Flowchart: Print all permutations of a given string

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Python Code Editor:

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Python: Tips of the Day

Getting rid of unwanted characters:

You can get rid of whitespaces or any specific character using strip methods in Python. You can use either plain strip for both sides, lstrip for the left side and rstrip for the right side only.

str="+++Welcome python+++"
str.strip()

print(str)

Output:

+++Welcome python+++