Is it possible to execute python commands passed as strings using python -c? can someone give an example.
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2 Answers
You can use -c to get Python to execute a string. For example:
python3 -c "print(5)"
However, there doesn't seem to be a way to use escape characters (e.g. \n). So, if you need them, use a pipe from echo -e or printf instead. For example:
$ printf "import sys\nprint(sys.path)" | python3
3 Comments
mattmc3
python3 -c "import sys; print(sys.path)" is simpler.
Kevin
@mattmc3 You can't end a block (where indentation would decrease) with a semicolon. So it's more limited; you can't, for example, create a function and then actually call it, or use an if-else, or even an if followed by unconditional code. But (where possible) that is simpler.
Mark Amery
I don't understand the remark about escape characters here. They seem to work completely fine and as I would expect them to. (Do you just mean to say that you can't write the two-character sequence
\n instead of a newline character to separate two statements in the script you pass to -c? Sure, you indeed can't do that, but why would you expect that to work?)For a single string you can use python -c. But for strings as the question asks, you must pass them to stdin:
$ python << EOF
> import sys
> print sys.version
> EOF
2.7.3 (default, Apr 13 2012, 20:16:59)
[GCC 4.6.3 20120306 (Red Hat 4.6.3-2)]
answered May 26, 2012 at 18:19
Ignacio Vazquez-Abrams
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3 Comments
honeybadger
I found the answer. just copy paste this on the terminal. python -c "import sys; x = 'hello world'; print x;"
Ignacio Vazquez-Abrams
That's a string. If you want strings then you need to feed them to stdin.
Mark Amery
I don't understand what this answer is trying to say. As far as I can tell there's no behaviour difference between piping a script into stdin or passing it as a
-c argument. The only guess I had at what you might mean was that perhaps Python would execute commands as it receives them on stdin - but nope, it seems it waits for the end of stdin and then executes the received script. So what do you mean?