Python in terminal: how to signify end of for loop?

Question

Say I want to print 0 through 9.

I type in for i in range(10): print(i), press enter, and terminal shows ..., waiting for further statements.

So I have to press enter again to have the numbers printed.

>>> for i in range(10): print(i)
...

How can I have the number printed without having to press enter twice?

Are you asking how to execute a command without pressing `enter` to execute your command...? — crookedleaf, Mar 08 '17 at 20:54
@crookedleaf No...So I type `for i in range(10): print(i)`, enter, and it gives `...` waiting for more statements. So I have to press enter twice. — kgf3JfUtW, Mar 08 '17 at 20:54
@SamShen this is just the way the terminal works since you are trying to execute a multi-line command on one line. it's waiting for confirmation that you are done. — crookedleaf, Mar 08 '17 at 20:57
Press enter after the command. You now only have to press enter once. — Denziloe, Mar 08 '17 at 20:58
@crookedleaf Thank you - yeah I just wondered if there's a way to signify "I'm done" using that one line. — kgf3JfUtW, Mar 08 '17 at 21:07

score 24 · Accepted Answer · answered Mar 08 '17 at 20:55

24

Just type the two returns and move on. But since you ask, this only needs one Enter:

exec("for i in range(10): print(i)")

answered Mar 08 '17 at 20:55

alexis

48,685
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score 7 · Answer 2 · answered Jun 01 '19 at 18:22

7

"alt+enter" I was working in ipython and facing the same problem as yours. upon trying various combinations from keyboard, this one finally worked

answered Jun 01 '19 at 18:22

Paarmita

81
1
1

2

I don't think this works in the regular python terminal which is different than iPython terminal – Matthew Barlowe Jun 01 '19 at 18:29
For reference, this works in the standard Mac OS terminal, except that the keys become `option+enter`. – Seb Apr 12 '22 at 06:39

score 2 · Answer 3 · edited Feb 21 '20 at 08:13

2

You can use the Shift+Enter to end the function or loop which continues next line as below:

edited Feb 21 '20 at 08:13

Flickerlight

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answered Feb 21 '20 at 06:01

Guest User

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1

score 0 · Answer 4 · answered Aug 11 '20 at 11:32

Convert your for-loop into a so-called list comprehension (you don't need eval / exec and wrap the whole thing in a string as the current top answer suggests):

In [1]: [i for i in range(3)]
Out[1]: [0, 1, 2]

You can also keep your print() statement if you want it on multiple lines, but the return value (None) will be put in the array that is returned, so you'll get this:

In [2]: [print(i) for i in range(3)]
0
1
2
Out[2]: [None, None, None]

To suppress that final output line, you can add a semicolon:

In [3]: [print(i) for i in range(3)];
0
1
2

So much for ipython3, but perhaps more usefully, what about command-line usage? You can't do python3 -c 'import sys; for line in sys.stdin: print(line)' but you can use list comprehension:

$ python3 -c '[print(i) for i in range(3)]'
0
1
2

So if you want to run a bit of python over each line:

$ cat inputfile
two
examples
$ cat inputfile | python3 -c 'import sys; [print(line.strip().upper()) for line in sys.stdin]'
TWO
EXAMPLES

(You can replace cat infile | with <infile but this seemed more accessible for those not familiar with Bash syntax, and those who are familiar can trivially replace it.)

score 0 · Answer 5 · answered Jan 23 '21 at 16:05

0

You can execute the for statement without using the exec() by pressing enter to go to the next line and then pressing ctrl + d

answered Jan 23 '21 at 16:05

Salman

9
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Python in terminal: how to signify end of for loop?

5 Answers5