Python: Find the shortest distance from a specified character in a given string

Last update on May 28 2022 13:00:31 (UTC/GMT +8 hours)

Python Itertools: Exercise-23 with Solution

Write a Python program to find the shortest distance from a specified character in a given string. Return the shortest distances through a list and use itertools module to solve the problem.

Sample Solution:

Python Code:

import itertools as it

def char_shortest_distancer(str1, char1):
    result = [len(str1)] * len(str1)
    prev_char = -len(str1)
    for i in it.chain(range(len(str1)),reversed(range(len(str1)))):
        if str1[i] == char1:
            prev_char = i
        result[i] = min(result[i], abs(i-prev_char))
    return result

str1 = "w3resource"
chr1='r'
print("Original string:",str1,": Specified character:",chr1)
print(char_shortest_distancer(str1,chr1))

str1 = "python exercises"
chr1='e'
print("\nOriginal string:",str1,": Specified character:",chr1)
print(char_shortest_distancer(str1,chr1))


str1 = "JavaScript"
chr1='S'
print("\nOriginal string:",str1,": Specified character:",chr1)
print(char_shortest_distancer(str1,chr1))

Sample Output:

Original string: w3resource : Specified character: r
[2, 1, 0, 1, 2, 2, 1, 0, 1, 2]

Original string: python exercises : Specified character: e
[7, 6, 5, 4, 3, 2, 1, 0, 1, 0, 1, 2, 2, 1, 0, 1]

Original string: JavaScript : Specified character: S
[4, 3, 2, 1, 0, 1, 2, 3, 4, 5]

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Python program to create a 24-hour time format (HH:MM ) using 4 given digits. Display the latest time and do not use any digit more than once.
Next: Write a Python program to find the maximum length of a substring in a given string where all the characters of the substring are same. Use itertools module to solve the problem.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.

Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

The os and os.path modules.
The __file__ constant
os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
os.path.dirname(path) (returns "the directory name of pathname path")
os.getcwd() (returns "a string representing the current working directory")
os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m