Python 子进程不同的方法

Question

I have the following structure

- folder1
-- script1.py
- folder2
-- script2_1.py
-- script2_2.py
- folder2
-- script3.py

script2_1.py has the following line in it

os.system("python3 script2_2.py "+str(id))

If I SSH into the instance, cd to folder2 and then run script2_1.py

python3 script2_1.py

it works fine and script2_2.py is called as expected.

---

Now in script1.py I want to call both script2_2.py and script3.py. I've tested different approaches but no success yet.

Approach 1 :

id = str(id)
subprocess.check_call(["/folder2", "script2_2.py "+id])
subprocess.check_call(["/folder3", "script3.py "+id])

which gives

PermissionError: [Errno 13] Permission denied: '/folder2'

Approach 2:

id = str(id)
commands = '''
cd /folder2/ 
python3 script2_2.py {} 
cd /folder3/ 
python3 script3.py {} 
'''.format(id, id)
p = subprocess.Popen("/bin/sh", stdin=subprocess.PIPE, stdout=subprocess.PIPE)
out, err = p.communicate(commands.encode('utf-8'))

which gives

/bin/sh: python3: not found

Approach 3:

id = str(id)
subprocess.call(['cd /folder2/','python3 script2_2.py {}'.format(id)])
subprocess.call(['cd /folder3/','python3 script3.py {}'.format(id)])

which gives

FileNotFoundError: [Errno 2] No such file or directory: 'cd /folder2/': 'cd /folder2/'

Approach 4 :

In this one I've tested args with both string and list, specifying the full path to the.py file, with and without shell=True, without sys.path and with full path in subprocess.call, ...

id = str(id)
#import sys
#sys.path.insert(1, '/folder2/')
subprocess.call(['/usr/local/bin/python3','/folder2/script2_2.py {}'.format(id)])
#sys.path.insert(1, '/folder3/')
subprocess.call(['/usr/local/bin/python3','/folder3/script3.py {}'.format(id)])

which gives

/usr/local/bin/python3: can't open file '/folder2/script2_2.py 80': [Errno 2] No such file or directory

/usr/local/bin/python3: can't open file '/folder3/script3.py 80': [Errno 2] No such file or directory

Answer 1

Eventually I manage to solve it by using and adaptation of Approach 2 with the full path to python3.

id = str(id)
commands = '''
cd /folder2/ 
/usr/local/bin/python3 script2_2.py {} 
cd /folder3/ 
/usr/local/bin/python3 script3.py {} 
'''.format(id, id)
p = subprocess.Popen("/bin/sh", stdin=subprocess.PIPE, stdout=subprocess.PIPE)
out, err = p.communicate(commands.encode('utf-8'))

To know which one is I SSH into the instance and ran

which python3

which returned

/usr/local/bin/python3