python - whats the difference between .communicate() and .communicate()[0]? -


i'm using python. i'm trying run process , fetch output using subprocess.popen. after reading around see people using communicate()[0] thats not in docs, used in example. i'm wondering if fill me in why 1 append [0] communicate()?

from docs:

popen.communicate(input=none)

interact process: send data stdin. read data stdout , stderr, until end-of-file reached. wait process terminate. optional input argument should string sent child process, or none, if no data should sent child.

communicate() returns tuple (stdoutdata, stderrdata).

so communicate()[0] used access stdoutdata , communicate()[1] access stderrdata

to access elements in tuple or list use indexes, first element @ index 0.

>>> tup = ("foo", "bar") >>> tup[0] 'foo' >>> tup[1] 'bar'

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