Python执行shell并打印stdout

Question

printing stdout[1] prints only single character. How to print single line instead of single character?

pr = subprocess.Popen(args=['./check.sh'], bufsize=1, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)

(stdout, stderr) = pr.communicate(input=None)

print(stdout[1])

Answer 1

Depends on how your check.sh looks. But if it's something simple, say:

#check.sh
echo "foo"
echo "bar"

Then you can decode() (from bytes to string) and split on newlines ( \\n ):

stdout.decode().split("\n")[0] # foo

Answer 2

An alternative way that could be faster on large outputs, or when streaming output is to consider itertools

from itertools import takewhile
print("".join(takewhile(lambda x: x != "\n", stdout)))

This will keep feeding characters into the join function until it finds a newline character, or the end of the output.

It's worth noting that this specific implementation of the solution will only work with the first line of the output - so adjust accordingly.