Unable to edit list after converting from tuple

Question

I'm using the code below:

a = ('Monty Python', 'British', 1969) #a is a tuple
b=list(a) #this should convert it to a list if I'm not wrong
print(b) #the output till here is okay
c=b.append("abcd") 
print(c) # the output for this is None

Can anyone explain why am I unable to edit after converting the tuple to a list??

`append` doesn't return the output list. It modifies the old one. — Black Thunder, Oct 22 '18 at 08:53

score 0 · Accepted Answer · answered Oct 22 '18 at 08:54

0

.append() does not return a list.

You are doing c = b.append("abcd"), this makes no sense because b.append() does not return a list, it returns none.

Try print(type(b.append("abcd"))) and see what it prints. So as you can see python is working correctly.

Things like .append() .pop() do not return a new list, they change the list in memory.

This is called an inplace operation I believe

answered Oct 22 '18 at 08:54

Alexis Drakopoulos

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Thank you so much! I was assigning it so something else unnecessarily. – Mohd Abdul Mukheem Oct 22 '18 at 09:02

score 0 · Answer 2 · answered Oct 22 '18 at 08:55

0

You're printing c whose job is to append. Print b instead, that's your list.

answered Oct 22 '18 at 08:55

Muhammad Hamza

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Thank you for that! It helped – Mohd Abdul Mukheem Oct 22 '18 at 09:03

Unable to edit list after converting from tuple

2 Answers2