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Python Python Collections (Retired) Lists Redux Manipulating Lists

Warren Chisasa
Warren Chisasa
3,731 Points

Use of 'pop' and 'insert' function

I am trying to remove the first element of my list then add 1 to it by using the pop and insert function in one step but I keep getting the 'bummer'. Requesting for any suggestions on how to deal with this code.

lists.py
the_list = ["a", 2, 3, 1, False, [1, 2, 3]]
new_list = the_list.pop(0).insert(0,1)
print(new_list)



# Your code goes below here

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,064 Points

In your code, the pop(0) removes the first object from the list and returns it. This is the string "a". It is this object that is referenced by the insert() method. Strings do not have this method so it raises an error.

new_list = the_list.pop(0).insert(0,1)

Instead, use each method separately so they can operate directly on the list.

the_list = ["a", 2, 3, 1, False, [1, 2, 3]]
the_list.pop(0)  # remove string
the_list.insert(0, the_list.pop(2)) #  remove 1, insert at first position