Homework 4 regular expressions

 Homework 4 
In this assignment, you will write four functions that use regular expressions. For Problem 4,
you need to first download the Dodds et al happiness dictionary, happiness dictionary.py.
Instructions: Name your file hw4.py and submit on CCLE. Add comments to each function.
• Problem 1:
Write a function mytype(v) that performs the same action as type(), and can recognize integers, floats, strings, and lists. Do this by first using str(v), and then reading
the string. Assume that lists can only contain numbers (not strings, other lists, etc...),
and assume that strings can be anything that is not an integer, float or list. Note that
an empty list [] should also be recognized as a list.
Test cases:
mytype(10) and mytype(-10) should return "int";
mytype(-1.25) and mytype(10.0) should return "float";
mytype([1, 2, 3]) and mytype([]) should return "list";
mytype("abc") and mytype({1,2}) should return "string";
• Problem 2:
Write a function findpdfs(L) that takes as input a list L of filenames (such as
“IMG2309.jpg”, “lecture1.pdf”, “homework.py”), and returns a list of the names of
all PDF files, without extension (“lecture1”). Assume that filenames may contain only
letters and numbers.
Test case:
L = ["IMG2309.jpg", "lecture1.pdf", "homework.py", "homework2.pdf"]
findpdfs(L) should return ["lecture1", "homework2"].
• Problem 3:
Write a function findemail(url) that takes as input a URL, and outputs any email
addresses that look like “xxx@xxx.xxx.xxx” with any number of dots after the @-sign
on this page. The order of the email addresses in the output doesn’t matter. Your
function should also get around tricks people use to hide their email addresses, such as
hangjie@math.ucla.edu
hangjie AT math DOT ucla DOT edu
hangjie at math dot ucla dot edu
hangjie[AT]ucla[DOT]edu
hangjie[at]ucla[dot]edu
Test cases:
url1 = "https://www.math.ucla.edu/~hangjie/contact/"
url2 = "https://www.math.ucla.edu/~hangjie/teaching/Winter2019PIC16/regexTest"
findemail(url1) should return ["hangjie@math.ucla.edu"];
findemail(url2) should return ["hangjie1@math.ucla.edu",
"hangjie2@math.ucla.edu", "hangjie3@math.ucla.edu",
"hangjie4@ucla.edu","hangjie5@ucla.edu","xxx@xxx.xxx.xxx"].
Due 5 PM, Friday, November 1 Homework 4 PIC 16
• Problem 4:
Write a function happiness(text) that uses the Dodds et al [1] happiness dictionary
to rate the happiness of a piece of english text (input as a single string). The happiness
score is the average score over all words in the text that appear in the dictionary. For
simplicity, you may neglect the words with special characters in the dictionary.
Test cases:
s1 = "Mary had a little lamb."
s2 = "Mary had a little lamb. Mary had a little lamb!"
s3 = "A quick brown fox jumps over a lazy dog."
happiness(s1) and happiness(s2) should return 5.368;
happiness(s3) should return 5.275.
References
[1] Peter Sheridan Dodds, Kameron Decker Harris, Isabel M Kloumann, Catherine A Bliss,
and Christopher M Danforth. Temporal patterns of happiness and information in a global
social network: Hedonometrics and twitter. PloS one, 6(12):e26752, 2011.