What's the different between 'list((x,)).extend([x])' and 'foo=list((x,)); foo.extend([x])'
- Ran
print(list((1,)).extend([2])), the output isNone. - Ran
foo=list((1,)); foo.extend([2]);print(foo), the output is[1, 2].
I don't know whats the different, Please help to check it, thanks.
python
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
asked Nov 12 '18 at 3:41
joeysjoeys
1
add a comment |
- Ran
print(list((1,)).extend([2])), the output isNone. - Ran
foo=list((1,)); foo.extend([2]);print(foo), the output is[1, 2].
I don't know whats the different, Please help to check it, thanks.
python
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
asked Nov 12 '18 at 3:41
joeysjoeys
1
2
The first one you're not printing the list, you're printing the return value ofextendwhich is none.
– Loocid
Nov 12 '18 at 3:44
add a comment |
- Ran
print(list((1,)).extend([2])), the output isNone. - Ran
foo=list((1,)); foo.extend([2]);print(foo), the output is[1, 2].
I don't know whats the different, Please help to check it, thanks.
python
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
asked Nov 12 '18 at 3:41
joeysjoeys
1
- Ran
print(list((1,)).extend([2])), the output isNone. - Ran
foo=list((1,)); foo.extend([2]);print(foo), the output is[1, 2].
I don't know whats the different, Please help to check it, thanks.
python
python
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
asked Nov 12 '18 at 3:41
joeysjoeys
1
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
asked Nov 12 '18 at 3:41
joeysjoeys
1
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
edited Nov 12 '18 at 3:43
Carcigenicate
17.4k43058
17.4k43058
asked Nov 12 '18 at 3:41
joeysjoeys
1
asked Nov 12 '18 at 3:41
joeysjoeys
1
asked Nov 12 '18 at 3:41
joeysjoeys
1
1
2
The first one you're not printing the list, you're printing the return value ofextendwhich is none.
– Loocid
Nov 12 '18 at 3:44
add a comment |
2
The first one you're not printing the list, you're printing the return value ofextendwhich is none.
– Loocid
Nov 12 '18 at 3:44
2
2
The first one you're not printing the list, you're printing the return value of
extend which is none.– Loocid
Nov 12 '18 at 3:44
The first one you're not printing the list, you're printing the return value of
extend which is none.– Loocid
Nov 12 '18 at 3:44
add a comment |
2 Answers
2
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oldest
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The extend() method only modifies the original list. It doesn't return any value. Thus print() couldn't receive anything, and output 'None'.
answered Nov 12 '18 at 3:44
lsvlsv
47739
add a comment |
In the first snippet, you're printing what extend returns: None. In the second snippet, you're printing foo, the list itself.
Or in other words, in the first, you're printing the result of a function call that doesn't return anything. In the second, you're carrying out the extend call, then printing the list separately.
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
add a comment |
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The extend() method only modifies the original list. It doesn't return any value. Thus print() couldn't receive anything, and output 'None'.
answered Nov 12 '18 at 3:44
lsvlsv
47739
add a comment |
The extend() method only modifies the original list. It doesn't return any value. Thus print() couldn't receive anything, and output 'None'.
answered Nov 12 '18 at 3:44
lsvlsv
47739
add a comment |
The extend() method only modifies the original list. It doesn't return any value. Thus print() couldn't receive anything, and output 'None'.
answered Nov 12 '18 at 3:44
lsvlsv
47739
The extend() method only modifies the original list. It doesn't return any value. Thus print() couldn't receive anything, and output 'None'.
answered Nov 12 '18 at 3:44
lsvlsv
47739
answered Nov 12 '18 at 3:44
lsvlsv
47739
answered Nov 12 '18 at 3:44
lsvlsv
47739
answered Nov 12 '18 at 3:44
lsvlsv
47739
47739
add a comment |
add a comment |
In the first snippet, you're printing what extend returns: None. In the second snippet, you're printing foo, the list itself.
Or in other words, in the first, you're printing the result of a function call that doesn't return anything. In the second, you're carrying out the extend call, then printing the list separately.
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
add a comment |
In the first snippet, you're printing what extend returns: None. In the second snippet, you're printing foo, the list itself.
Or in other words, in the first, you're printing the result of a function call that doesn't return anything. In the second, you're carrying out the extend call, then printing the list separately.
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
add a comment |
In the first snippet, you're printing what extend returns: None. In the second snippet, you're printing foo, the list itself.
Or in other words, in the first, you're printing the result of a function call that doesn't return anything. In the second, you're carrying out the extend call, then printing the list separately.
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
In the first snippet, you're printing what extend returns: None. In the second snippet, you're printing foo, the list itself.
Or in other words, in the first, you're printing the result of a function call that doesn't return anything. In the second, you're carrying out the extend call, then printing the list separately.
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
answered Nov 12 '18 at 3:45
CarcigenicateCarcigenicate
17.4k43058
17.4k43058
add a comment |
add a comment |
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The first one you're not printing the list, you're printing the return value of
extendwhich is none.– Loocid
Nov 12 '18 at 3:44