Create reusable functions
There's currently no way to import (parts of) the code and reuse it in a different program. Other than that, splitting up your logic into functions will make it easier to test and debug.
For instance, rather than getting the alphabet and adding the letters to it one by one and checking if the current first letter matches the last in that list, use a generator function to get the first next function each time:
def alphabet_counter():
for letter in string.ascii_lowercase:
yield letter
and use it as follows:
expected_letter = alphabet_counter()
if word[0] == next(expected_letter):
# the current word's first letter matches the expected letter of the alphabet.
This also means you don't have to use a special check for the very first letter, because the first time you use the next(expected_letter) call, you get a, the second time b, etc.
The next step would be to add if __name__ == '__main__': to your function. This will allow you to either import the code in the file, or to simply run it as a script. For example:
def is_valid_wordchain():
# code here ...
if __name__ == '__main__':
is_valid_wordchain()
You can now import your function to another script / project and reuse the code, or you can run it as a script and is_valid_wordchain() will be called and executed.
- As Carra's answer already pointed out, you could call
lower() once on the word, and then check in the if-statements without having to call lower all the time.
- Be consistent in your variable naming. You used the Dutch
woord as variable name for a word, but the rest of your variables / output is in English.
- Never asssume that input given from the user is OK. Build in checks to make sure that when expecting an integer, you get an integer. For example in your code:
for i in range(words):
word = input()
# rest of code ..
.. it is assumed that the given input is correct. I could enter an integer and the program crashes. The same goes for the words = int(input()). If I enter some string on the first line when running the program, I get a ValueError: invalid literal for int() with base 10: 'some string' which crashed the program.
- Since it is immediately checked upon entering the word if the wordchain is still correct, why not stop the program? If I were to enter 10+ words, but it already silently fails on the 2nd word, I'd still have to enter 8+ words to find out.
The program with the proposed changes
import re
import string
def is_valid_word(word):
"""Checks whether or not the given string is a valid word."""
return isinstance(word, str) and re.match(r'\b[\w\']+\b', word)
def get_word_amount():
"""Get the amount of words in the wordchain from the user."""
while True:
try:
return int(input('How many words are in the chain? '))
except ValueError:
print('Not a valid number, try again.\n')
def get_word_from_user(count):
"""Get a single word from the user."""
while True:
word = input('Please type word #{}: '.format(count))
if is_valid_word(word):
return word
else:
print('Not a valid word, try again.\n')
def alphabet_counter():
"""Iterate through the alphabet"""
for letter in string.ascii_lowercase:
yield letter
def is_valid_wordchain():
"""
Allow the user to enter a number of words to be checked if it forms
a valid wordchain.
A wordchain is correct if for every word in the chain, the first
and last letter match, and the words are in alphabetical order.
"""
word_amount = get_word_amount()
expected_letter = alphabet_counter()
word_list = [] # only for record keeping; has no value in checking.
for number in range(word_amount):
word = get_word_from_user(number + 1).lower()
if word[0] != word[-1] or word[0] != next(expected_letter):
print('Incorrect wordchain. Failed at "{}"'.format(word))
return
else:
word_list.append(word)
print('Correct wordchain!\n{}'.format(word_list))
if __name__ == '__main__':
is_valid_wordchain()
