Quiz1Problem8.py

# Quiz1Problem8.py
# edX MITx 6.00.1x
# Introduction to Computer Science and Programming Using Python
# Quiz 1, Problem 8

'''
Write a Python function called satisfiesF that has the specification below.
Then make the function call run_satisfiesF(L, satisfiesF).
Your code should look like:

def satisfiesF(L):
    """
    Assumes L is a list of strings
    Assume function f is already defined for you and it maps a string to a Boolean
    Mutates L such that it contains all of the strings, s, originally in L such
            that f(s) returns True, and no other elements
    Returns the length of L after mutation
    """
    # Your function implementation here

run_satisfiesF(L, satisfiesF)
'''

# For your own testing of satisfiesF, for example, the following test function f and test code:
#
# def f(s):
#     return 'a' in s
#
# L = ['a', 'b', 'a']
# print satisfiesF(L)
# print L
#
# Should print:
#
# 2
# ['a', 'a']
# Paste your entire function satisfiesF, including the definition, in the box
# below. After you define your function, make a function call to
# run_satisfiesF(L, satisfiesF). Do not define f or run_satisfiesF. Do not leave
# any debugging print statements.
#
# For this question, you will not be able to see the test cases we run. This
# problem will test your ability to come up with your own test cases.


def satisfiesF(L):
    """
    Assumes L is a list of strings
    Assume function f is already defined for you and it maps a string to a Boolean
    Mutates L such that it contains all of the strings, s, originally in L such
            that f(s) returns True, and no other elements
    Returns the length of L after mutation
    """
    # Your function implementation here

    # Create a copy of L to iterate over
    newList = L[:]

    # Iterate over the copy of the list newList, make any changes to L
    for i in newList:
        if f(i)==False:
            L.remove(i)
    # Debug statement, comment out before submitting
    # print L
    return len(L)

# For testing only, remove before submitting
def f(s):
    return 'a' in s

# Testing values, comment out before submitting
L = ['a', 'b', 'a']
print satisfiesF(L)
print L

# Calling run_satisfiesF(), leave in when submitting
run_satisfiesF(L, satisfiesF)