How to Generate Permutations of a String Using Python\'s `itertools.permutations()`?

Finding Permutations of a String with itertools.permutations()

When faced with generating all permutations of a given string, it's tempting to resort to manual techniques involving iterating over characters and swapping them. However, Python's itertools module offers an elegant solution through the permutations() method.

Iteratortools.permutations() accepts an iterable, such as a string, and returns successive length permutations of its elements. By default, it generates full-length permutations, but you can specify a desired length with the r parameter.

To obtain all permutations of a string in Python, simply utilize the following code:

from itertools import permutations

string = 'stack'

# Get all permutations as tuples
perms = permutations(string)

# Convert permutations to strings for readability
perms_as_strings = [''.join(p) for p in perms]

This approach yields a list containing all possible permutations of the given string.

Note that the order of permutations in the list is lexicographic. This means that if your string is sorted, the permuted strings will also be sorted.

Handling Duplicates

If your string contains duplicate characters, the permutations() method will generate duplicates as well. To eliminate duplicates, you can convert your list of permutations to a set:

perms_as_strings = set(perms_as_strings)

This set will now contain only unique permutations. However, it's important to note that the order of elements is lost when converting to a set.

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