如何将打印（subprocess.checkout）的输出存储到 Python 中的变量？

Question

I have the below print statement

print(subprocess.check_output(['bash', '-c', shell_script], stdin=open('/etc/fstab', 'r')))

that prints few lines like '/xyz NOT mounted' and I would like to store it into a variable just like how the lambda function does it.

out = lambda: print("/xyz NOT mounted")
out()

I would then need to use that variable to write an if statement as in if out contains any string, then print contains string, else contains nothing

Answer 1

Could you please try following, tested and written in Python2.7

#!/usr/bin/python
import re
out="/xyz NOT mounted"
if re.search(r'[a-zA-Z]+', out):
    print "String found."
else:
    print "String NOT found."

When value of variable out is having string values it prints String found.

---

---

Now lets test it with NULL value of variable val here.

cat script.py
#!/usr/bin/python
import re
out=""
if re.search(r'[a-zA-Z]+', out):
    print "String found."
else:
    print "String NOT found."

When we run above then it gives as String NOT found.

Answer 2

I cannot run your code on my machine because I miss the shell_script part.

For similar cases I use subprocess.PIPE and collect the output lines in a list that you can iterate and check later:

import subprocess

def bash_command(cmd):
    sp = subprocess.Popen(['/bin/bash', '-c', cmd], stdout=subprocess.PIPE)
    return sp.stdout.readlines()

result = bash_command('ls') # Insert here your bash command

for line in result:
    if "NOT mounted" in line:
        print("Hey I have a line containing NOT mounted")
    else:
        print("Hey I have a line not containing NOT mounted")

Answer 3

can you not just save the variable and then print it?

 x = subprocess.check_output()
 print(x)

 #and then...
 if x == ???:
    #do something

Saving the variable and printing it seems a lot easier than trying to grab hold of the print statements' output.

Answer 4

Here, an example to execute a command using subprocess and store and output/buffer data in a variable.

Ex:

Command_Input = subprocess.Popen("Your Command",stdin=process_output.stdout, stdout=subprocess.PIPE, shell=True)
Command_Output = Command_Input.communicate()[0]
Print(Command_Output)