CODEWITHSUNDEEP
pythonbashipython
mwaskom
mwaskom

Reputation: 49002

Pipe data into IPython and remain in the session after processing it

I would like to pipe some data into the ipython terminal client, run a command, and then stay in the session.

In terms of passing an argument into IPython, running a command, and keeping the session alive, this works:

[~]$ ipython -i -c "import sys; print(sys.argv[-1])" "my,testcsv\n1,2,3"
Python 3.7.3 (default, Mar 27 2019, 16:54:48)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.23.1 -- An enhanced Interactive Python. Type '?' for help.
my,test,csv\n1,2,3

In [1]:

But adding a pipe both raises an exception in Python and immediately quits back to the shell:

[~]$ echo "my,test,csv\n1,2,3" | ipython -i -c "import sys; print(sys.argv[-1])"
Python 3.7.3 (default, Mar 27 2019, 16:54:48)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.23.1 -- An enhanced Interactive Python. Type '?' for help.
import sys; print(sys.argv[-1])

In [1]:   File "<ipython-input-1-f826f34ba2b7>", line 1
    my,test,csv\n1,2,3
                      ^
SyntaxError: unexpected character after line continuation character


In [2]: Do you really want to exit ([y]/n)?
[~]$                                 ^

And using xargs processes the input correctly, but it also immediately quits back to the shell:

[~]$ echo "my,test,csv\n1,2,3" | xargs -0 ipython -i -c "import sys; print(sys.argv[-1])"
Python 3.7.3 (default, Mar 27 2019, 16:54:48)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.23.1 -- An enhanced Interactive Python. Type '?' for help.
my,test,csv\n1,2,3


In [1]: Do you really want to exit ([y]/n)?
[~]$

Is there a way to accomplish what I'm after here?

Upvotes: 1

Views: 237

Answers (1)

wjandrea
wjandrea

Reputation: 32954

I think it's exiting when it reads EOF from stdin. true | ipython -i also exits immediately. For that matter, so does true | python -i.

Instead you could use process substitution to get the command's stdout as a file.

tmp.py:

import sys

fname = sys.argv[-1]
with open(fname) as f:
    print(f.read())

$ ipython --no-banner -i tmp.py <(echo "foo")
foo


In [1]:

Upvotes: 1

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