![]() Now len() is 2, hence the else branch of the if is taken. This is trivial, since len(') is 1 then the first branch of the if condition is taken and the return value is itself (this complies with rule 2.1). Returns: a list of all permutations of sequence ''' if len (sequence) 1: return list (sequence) else: chartoinsert sequence :1 remainder sequence 1: subpermutations getpermutations (remainder) permutations for permutation in subpermutations: strlen len (permutation) for i in range (0, strlen + 1): front permu. Now we try to 'mental execute' it in order to shed some light for the absolute beginner. The program is a straightforward (possibly inefficient, see the remarks at the bottom of the page) implementation of the recursive algorithm. Here's a slightly improved version of illerucis's code for returning a list of all permutations of a string s with distinct characters (not necessarily in lexicographic sort order), without using itertools: def getperms(s, i0): ''' Returns a list of all (len(s) - i) permutations t of s where t:i s:i. Trying to Understand the Code by 'Mental Execution' Code: import math def getpermutations (sequence): Enumerate all permutations of a given string sequence (string): an arbitrary string to permute. The next variable length holds how many characters there are to go till the string is the right length. Use the permutation function to find all. Allow user to input the string and assign it in a variable. Use the folloiwng steps and write a python program to print all permutations of a given string: First of all, import the permutation function from the python itertools module in program. ![]() ![]() The variable string holds the current guess up to this point, so in the first example, string will be everything up to bob such as ab, bo etc. 1: Find all permutations of a string in Python. Such code is not mine, it is the original snippet the OP was asking for explanations (as a matter of fact, I am more inclined towards Lua than Python and I had to lookup the enumerate function in Python's documentation in order to fully understand the code). We always call each function with the three variables: string, length and goal. A string of length n has n permutation ( Source: Mathword ) Below are the permutations of string ABC. ![]()
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