Your order, please

your_order_please.py

"""
# Your order, please
# 
# Sort a given string. Each word in the String will contain a single number. This number is the position the
# word should have in the result.
# 
# Note: Numbers can be from 1 to 9. So 1 will be the first word (not 0).
#
# If the input String is empty, return an empty String. The words in the input String will only contain valid
# consecutive numbers.
# 
# For an input: "is2 Thi1s T4est 3a" the function should return "Thi1s is2 3a T4est"
"""

def find_number(word):
  index = 0
  if word[index].isdigit():
    return int(word[index])
  return find_number(word[index + 1: ])

def order(sentence):
  return " ".join(sorted(sentence.split(), key=find_number))

I've since found this more elegant version of the solution to this problem that I think captures the same concepts I tried to put into practice.

• solution as a function of a series of transformations
• avoid iteration
• avoid mutations and side effects

def order(sentence):
  return ' '.join(sorted(sentence.split(), key=lambda w: int(filter(str.isdigit, w))))