discussion-unit-5.py

# **************************
# CS1101 - Discussion Unit 5
# **************************

# **************************
# Instructions
# 1. Check whether its argument has any lowercase letters
# 2. Describe what it actually does when called with a string argument and if it does not correctly check for lowercase letters.
# 4. Give an example argument that produces incorrect results. (SEE BOTTOM for 3 calls to all functions!)
# 5. Describe why the result is incorrect. (SEE inline comments)
# **************************



# **************************
# Decides on the first letter and breaks the for..in loop once it's True or False
# Roger == False, because of R,
# oger == True, because of o
# ogeR == True, because of o; doesn't keep looking.
def any_lowercase1(s):
    for c in s:
        if c.islower():
            return True
        else:
            return False


# **************************
# 'c' is a string. It is passing a string not c the variable, which means it's always true, because 'c' is lowercase.
def any_lowercase2(s):
    for c in s:
        # Lowercase is true every time.
        if 'c'.islower():
            return 'True'
        else:
            return 'False'


# **************************
# A. 'flag' (inner variable) is declared inside the scope of the for..in loop and it's scope doesn't extend to the parent scope of the function.
# B. name 'flag' (outer variable) is not defined. It's irrelevant.
def any_lowercase3(s):
    for c in s:
        flag = c.islower()
    return flag


# **************************
# Once the `flag` is found to be True it can't be reassigned. First 'truth' means all are True.
def any_lowercase4(s):
    flag = False
    for c in s:
        flag = flag or c.islower()
    return flag


# **************************
# Will check if string has an uppercase and when True, then break the for..in loop with a False.
def any_lowercase5(s):
    for c in s:
        # Iterates continuously inside this loop until the return False on any single uppercase
        if not c.islower():
            return False
        # All iterations succeed without a return and then the function exits the for..in and returns True.
    return True
# **************************
# **************************
# **************************


# **************************
# Program manager
# Runs all the functions with the test strings in series and prints them.
# **************************
def test_lowercase_list(funcs):
    #i when, func what is called, func('xxx') results printed
    for i, func in enumerate(funcs): # (Hunner, T., 2016)
        # prints index number with string test, function and function call result.
        print(f'{i}**  Roger:', func, func('Roger'))
        print(f'{i}**  oger:', func, func('ogerc'))
        print(f'{i}**  rogeR:', func, func('rogeR'))
        print('\n')

# **************************
# list of functions above
list_funcs = [any_lowercase1, any_lowercase2, any_lowercase3, any_lowercase4, any_lowercase5]

# This function iterates over all the functions from list_funcs
test_lowercase_list(list_funcs)
# **************************
# **************************
# **************************


# **************************
# OUTPUT
# **************************

# 0**  Roger: <function any_lowercase1 at 0x7f983f5b91f0> False
# 0**  oger: <function any_lowercase1 at 0x7f983f5b91f0> True
# 0**  rogeR: <function any_lowercase1 at 0x7f983f5b91f0> True


# 1**  Roger: <function any_lowercase2 at 0x7f9840921820> True
# 1**  oger: <function any_lowercase2 at 0x7f9840921820> True
# 1**  rogeR: <function any_lowercase2 at 0x7f9840921820> True


# 2**  Roger: <function any_lowercase3 at 0x7f98409218b0> True
# 2**  oger: <function any_lowercase3 at 0x7f98409218b0> True
# 2**  rogeR: <function any_lowercase3 at 0x7f98409218b0> False


# 3**  Roger: <function any_lowercase4 at 0x7f9840921940> True
# 3**  oger: <function any_lowercase4 at 0x7f9840921940> True
# 3**  rogeR: <function any_lowercase4 at 0x7f9840921940> True


# 4**  Roger: <function any_lowercase5 at 0x7f98409219d0> False
# 4**  oger: <function any_lowercase5 at 0x7f98409219d0> True
# 4**  rogeR: <function any_lowercase5 at 0x7f98409219d0> False


# **************************
# Reference
# **************************
"""
Reference
Downey, A. (2015). Think Python: How to think like a computer scientist. Green Tree Press.
Hunner, T. (2016). "How to loop with indexes in Python". Retrieved from https://treyhunner.com/2016/04/how-to-loop-with-indexes-in-python/
"""