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Python Functional Python Functional Workhorses Map

Andy McDonald
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Andy McDonald
Python Development Techdegree Graduate 13,801 Points
Posted by Andy McDonald
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Andy McDonald
Python Development Techdegree Graduate 13,801 Points

Is a variable with a single letter Truthy?

Still having trouble with this quiz question. My for loop seems to be going but not adding to newword after it becomes what I think is truthy.

maps.py 
backwards = [
    'tac',
    'esuoheerT',
    'htenneK',
    [5, 4, 3, 2, 1],
]

def reverse(arg):
    letlist = []
    for char in arg:
        letlist.append(char)
    newword = None
    count = len(letlist)
    for i in range(count - 1, -1, -1):
        print('i =' + str(i))
        if newword:
            newword + letlist[i]
        else:
            newword = letlist[i]
    return newword

print(reverse('words'))

1 Answer

jb30
jb30
44,805 Points

A letter is truthy.

The line newword + letlist[i] does not change the value of newword. You could try newword += letlist[i].

With that change, your program would correctly reverse string inputs such as 'tac'. However, if you pass in [5, 4, 3, 2, 1], you will instead get 15, which is the sum of the array, and if you pass in ['t', 'a', 'c'], you will get 'cat' rather than ['c', 'a', 't'].