CODEWITHSUNDEEP
python
whatever
whatever

Reputation: 1227

How to append multiple items in one line in Python

I have:

count = 0
i = 0
while count < len(mylist):
    if mylist[i + 1] == mylist[i + 13] and mylist[i + 2] == mylist[i + 14]:
        print mylist[i + 1], mylist[i + 2]
    newlist.append(mylist[i + 1])
    newlist.append(mylist[i + 2])
    newlist.append(mylist[i + 7])
    newlist.append(mylist[i + 8])
    newlist.append(mylist[i + 9])
    newlist.append(mylist[i + 10])
    newlist.append(mylist[i + 13])
    newlist.append(mylist[i + 14])
    newlist.append(mylist[i + 19])
    newlist.append(mylist[i + 20])
    newlist.append(mylist[i + 21])
    newlist.append(mylist[i + 22])
    count = count + 1
    i = i + 12

I wanted to make the newlist.append() statements into a few statements.

Upvotes: 103

Views: 203644

Answers (8)

user3413723
user3413723

Reputation: 12213

Pretty simple. Surprisingly in python, you can just use +=

myList += newListItems

Example

myList = [1,2]
myList += [3,4]

print(myList) # prints [1,2,3,4]

Upvotes: 0

zakizakibzr
zakizakibzr

Reputation: 53

Use a for loop, it might look like this:

for x in [1,2,7,8,9,10,13,14,19,20,21,22]:
    new_list.append(my_list[i + x])

Upvotes: 1

Daring_T
Daring_T

Reputation: 166

If you are adding the same element then you can do the following:

["a"]*2
>>> ['a', 'a']

Upvotes: 0

Idrisi_Kasim
Idrisi_Kasim

Reputation: 91

Use this :

#Inputs
L1 = [1, 2]
L2 = [3,4,5]

#Code
L1+L2

#Output
[1, 2, 3, 4, 5]

By using the (+) operator you can skip the multiple append & extend operators in just one line of code and this is valid for more then two of lists by L1+L2+L3+L4.......etc.

Happy Learning...:)

Upvotes: 2

saoud rehman
saoud rehman

Reputation: 31

mylist = [1,2,3]

def multiple_appends(listname, *element):
    listname.extend(element)

multiple_appends(mylist, 4, 5, "string", False)
print(mylist)

OUTPUT: 

[1, 2, 3, 4, 5, 'string', False]

Upvotes: 3

Kevin Postlewaite
Kevin Postlewaite

Reputation: 615

You could also:

newlist += mylist[i:i+22]

Upvotes: 5

Karl Knechtel
Karl Knechtel

Reputation: 61498

No.

First off, append is a function, so you can't write append[i+1:i+4] because you're trying to get a slice of a thing that isn't a sequence. (You can't get an element of it, either: append[i+1] is wrong for the same reason.) When you call a function, the argument goes in parentheses, i.e. the round ones: ().

Second, what you're trying to do is "take a sequence, and put every element in it at the end of this other sequence, in the original order". That's spelled extend. append is "take this thing, and put it at the end of the list, as a single item, even if it's also a list". (Recall that a list is a kind of sequence.)

But then, you need to be aware that i+1:i+4 is a special construct that appears only inside square brackets (to get a slice from a sequence) and braces (to create a dict object). You cannot pass it to a function. So you can't extend with that. You need to make a sequence of those values, and the natural way to do this is with the range function.

Upvotes: 5

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798546

No. The method for appending an entire sequence is list.extend().

>>> L = [1, 2]
>>> L.extend((3, 4, 5))
>>> L
[1, 2, 3, 4, 5]

Upvotes: 263

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