Python Challenges: Takes a string of numbers and letters and return string which consists of letters

Last update on May 28 2022 13:09:13 (UTC/GMT +8 hours)

Python Challenges - 1: Exercise-51 with Solution

Write a Python program that takes a string of numbers and letters and return string which consists of letters.

Sample Solution:

Python Code:

def decode(str1):
    ints = "1234567890"

    num = ""
    letters = ""
    result_string = ""

    i = 0

    while i < len(str1):
    
        if str1[i] in ints:
            num += str1[i]
              
        else:
            letters += str1[i]

        i += 1

    for i, char in enumerate(num):

        result_string += int(char) * letters[i]

    return result_string
    
print(decode("4A3B2C1D2A"))
print(decode("4A3B2C1D3A"))
print(decode("1P1H1P"))
print(decode("4A3B3C1D2A1B1D4A1C"))

Sample Output:

AAAABBBCCDAA
AAAABBBCCDAAA
PHP
AAAABBBCCCDAABDAAAAC

Flowchart:

Python Code Editor:

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Previous: Write a Python program that takes a string and encode it that the amount of symbols would be represented by integer and the symbol.
Next: Write a Python program to find the largest palindrome made from the product of two 4-digit numbers

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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