Question

So I have a script like this

for key, Value in mydictionary.iteritems():
    if 'Mammal' in Value[1]: 
    #because the value is a list of 2 items and I want to get at the second one
        Value[1] = Value[1].strip('Mammal')

This code effectively removes Mammal from the beginning of the second item in the Value list. Now I want to make this nicer python looking with list comprehension so I came up with this but obviously is wrong…. Any help?

Value[1] = [Value[1].strip('Mammal') for Key, Value in mydictionary.iteritems() if 'Mammal' in Value[1] ]

Also, on the same lines, a list comprehension to list all the keys in this dictionary. I am having a hard time coming up with that one.

I came up with:

for key, Value in mydictionary.iteritems():
Templist.append(key)

but as a list comprehension I am thinking….but it doesn’t work 🙁

alist = [key for Key, Value in mydictionary.iteritems()]

Answer 1

mydictionary = {
    1: [4, "ABC Mammal"],
    2: [8, "Mammal 123"],
    3: [15, "Bird (Not a Mammal)"]
}

mydictionary = {key: ([value[0], value[1].strip('Mammal')] if 'Mammal' in value[1] else value) for key, value in mydictionary.iteritems()}
print mydictionary

Output:

{1: [4, 'ABC '], 2: [8, ' 123'], 3: [15, 'Bird (Not a Mammal)']}

Although I wouldn’t call this objectively “nicer looking”, so the iterative method may be preferable.