CPSC120A - Lab 17

Fuzzy Equals

Write the Python function fuzzy_equals(string1, string2) that determines if two strings are equal when capitalization and when leading and trailing whitespace are ignored. The parameters string1 and string2 are strings containing any text. The function should return True if the strings are the same when all leading and trailing whitespace characters (spaces, tabs, and return characters) are removed and when all capital letters are converted to lower case. It should return False otherwise.

Test Cases

print('Input: "?", "?"\t\tActual:', fuzzy_equals("?", "?"), '\tExpected: ?')

Swap Words

Write the Python function swap_words(text) that swaps the position of two words in a string. The parameter text is a string that contains two words. Assume that there is only one space character in text and it is between the two words. The function should return a new string with the position of the two words swapped. That is, the first word should become the second word and the second word should become the first word. The two words should still have a space character between them and there should not be any space characters at the begining or end.

Test Cases

print('Input: "?"\tActual: "' + swap_words("?") + '"\tExpected: "?"')

Input Sanitation

One of the biggest security vulnerabilities that web developers are constantly fighting is known as a SQL injection attack.. In this attack, users of a website format input in such a way that their input gets interpreted as code in the web developers systems. The easiest mechanism for preventing such an attack is to remove the offending characters before they get used in inappropriate ways.

Details

Write the Python function sanitize(text) that sanitizes text by removing all non-alphabetic characters. The parameter text is a string containing any text. The function should return a copy of text with all characters that are not letters removed.

Test Cases

print('Input: "?"\t\tActual: "' + sanitize("?") + '"\tExpected: "?"')

Use an accumulator to build the sanitized string from the input string one character at a time.
Test if a character is valid by using the in operator with the string "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".

Challenge

In the real world, the true offending characters are double and single quotes. Write a new function called escape_quotes(text) that returns a copy of text with all single or double quotes "escaped". Recall that a quote can be escaped in a string by pre-pending it with a backslash (\" or \').

Pig Latin Translator

Pig Latin is a somewhat silly language parody that is actually entirely English based. It is a simple transposition of letters that gives the effect of a "foreign" sounding language. The rules for converting an English word to Pig Latin are incredibly easy:

If the first character of the word is a vowel, append the string "yay" to the end.
If the first character is a consonant, then all consonants up to (but not including) the first vowel are moved to the end of the word. A ' character is placed between the transposed characters. Then the string "ay" is appended to the word.

Details

Write the Python function to_pig_latin(text) that converts English to Pig Latin. The parameter text is a string containing text in English. The function should return text converted to Pig Latin as a string.

Test Cases

print('Input: "?"\t\tActual:', to_pig_latin("?"), '\tExpected: ?')

Before converting the input text to Pig Latin, the function must find the index of the first vowel. Finding the index of the first vowel would be easier if there was a function that returned whether a single character is a vowel. So write the function is_vowel(character). The function has one parameter character an alphabetic string of length 1. The function should return True if character is 'a', 'e', 'i', 'o', or 'u' and False otherwise. Test this function before proceeding.
Finding the index of the first vowel requires traversing the text and testing whether each character is a vowel. Writing this as a separate function would make writing the translation function easier. So write the function index_of_first_vowel(text) that returns the index of first vowel in the specified text.
With the above two functions, writing the translation function is much easier. If the index of the first vowel is 0, then apply the first Pig Latin rule using concatenation. If the index of the first vowel is not 0, then apply the second Pig Latin rule using a slice and concatenation.

Challenge

Ofyay ourse'cay, ityay akes'may ittle'lay ense'say o'tay ite'wray ayay ogram'pray o'tay anslate'tray ayay ord'way o'tay ig'pay atin'lay ifyay ityay annot'cay anslate'tray ack'bay e'thay otheryay ay'way! Ite'wray ayay unction'fay om_pig_latin'fray at'thay akes'tay ayay ord'way alreadyyay inyay ig'pay atin'lay, andyay eturns'ray e'thay Englishyay equivalentyay.