Algorithms practice

reverse_phrase.py

#!/usr/bin/python
"""
Problem, Given a phrase, reverse every word preserving the order in the sentences

You could not use functions from the language.

Example
Input: Hello World From Mexico City
Output: olleH dlroW morF ocixeM ytiC

First Version: 2  Julio 2016
"""
# allow print() in python 2.x  otherwise it fails
from __future__ import print_function


def phrase2reverse(string):
    """
    Reverse an string without python libraries.
    :param string:
    :return:
    """
    reverse = ""
    index = len(string)
    for s in string:
        index -= 1
        reverse += string[index]
    return reverse

def to_output(list_phrases):
    """
    Generate the expected output
    :param list_phrases:
    :return:
    """
    output = ""
    for index, phrase in enumerate(list_phrases):
        if index == 0:
            output += "{}".format(phrase)
        else:
            output += " {}".format(phrase)
    return output

def text2reverse(text, sep=" "):
    """
    Reverse a text without library without python libraries.
    :param text:
    :param sep:
    :return:
    """
    list_phrases = []
    phrase = ""
    for char in text:
        if char == sep:
            list_phrases.append(phrase2reverse(phrase))
            phrase = ""
        else:
            phrase += char
    list_phrases.append(phrase2reverse(phrase))
    return to_output(list_phrases)

print(text2reverse("Hello World From Mexico City", sep=" ")) # sep " " is default so you can ommit it.
# output: olleH dlroW morF ocixeM ytiC