Question

Write a function called starts_with(prefix, wordlist) that takes as inputs a string prefix and a list of strings wordlist, and that uses a list comprehension to return a list consisting of all words from wordlist that begin with prefix. For example:
>>> starts_with('fun', ['functions', 'are', 'really', 'fun!'])
result: ['functions', 'fun!']

>>> starts_with('on', ['only', 'functions', 'on', 'the', 'brain'])
result: ['only', 'on'] # note that 'functions' is *not* included

>>> names = ['Alex', 'Adlai', 'Alison', 'Amalia', 'Anbita']
>>> starts_with('A', names)
result: ['Alex', 'Adlai', 'Alison', 'Amalia', 'Anbita']

>>> starts_with('Al', names)
result: ['Alex', 'Alison']

>>> starts_with('D', names)
result: []
Hints:

Your list comprehension will need an if clause.

Make sure that you only include words that start with the specified prefix. For instance, in the second example above, the string 'functions' is not included in the return value, because the string 'on' is in the middle of 'functions', rather than at the start. As a result, you won’t be able to use the in operator to test for the presence of the prefix in a word.

Answer 1

Answer:

Hi there! The question can easily be implemented by iterating through the array list an using the "startswith()" function of the String class. Please find explanation below.

Explanation:

We can write the code as below into a file called starts_with.py and run it from the command line. Sample input is also provided with results.

starts_with.py

import sys;

def starts_with(prefix, wordlist):

   for e in wordlist:

       if e.lower().startswith(prefix.lower()):

           starts_with_array.append(e);

starts_with_array = [];

prefix = input("Enter prefix: ");

wordlist = input("Enter word list: ");

wordlist = wordlist.split(',');

starts_with(prefix, wordlist);

print(starts_with_array);

Usage with Result

> starts_with.py

> Enter prefix: Fun

> Enter word list: Funtastic,Fun,Test,No

> ['Funtastic', 'Fun']