在python解释器和脚本文件中运行时的结果不同

Question

I am trying to use bash functions inside my python script to allow me to locate a specific directory and then grep a given file inside the directory. The catch is that I only have part of the directory name, so I need to use the bash function find to get the rest of the directory name (names are unique and will only ever return one folder)

The code I have so far is as follows:

def get_tag(part_of_foldername):
    import subprocess
    import os
    p1 = subprocess.Popen(["find", "/path/to/directory", "-maxdepth", "1", "-name", "%s.*" % part_of_foldername, "-type", "d"], stdout=subprocess.PIPE)
    directory = p1.communicate()[0].strip('\n')
    os.chdir(directory)
    p2 = subprocess.Popen(["grep", "STUFF_", ".hgtags"], stdout=subprocess.PIPE)
    tag = p2.comminucate()[0].strip('\n')
    return tag

Here is what's really strange. This code works when you enter it line by line into interactive, but not when it's run thru a script. It also works when you import the script file into interactive and call the function, but not when it's called by the main function. The traceback I get from running the script straight is as follows:

Traceback (most recent call last):
File "./integration.py", line 64, in <module>
    main()  
File "./integration.py", line 48, in main
    tag = get_tag(folder)
File "./integration.py", line 9, in get_date
    os.chdir(directory)
OSError: [Errno 2] No such file or directory: ''

And it's called in the main function like this:

if block_dict[block][0]=='0':
    tag = get_tag(folder)

with "folder" being previously defined as a string.

Please note we use python 2.6 so I can't use the module check_output unfortunately.

Answer 1

evidently p1.communicate()[0].strip('\\n') is returning an empty string. are you really using the hardcoded value "/path/to/directory" as in your example?

Answer 2

Have you tried using the glob module as opposed to find?

import glob
glob.glob("/path/to/directory/*/SomeDir/path/*")

You can look past multiple dirctories using **:

glob.glob("/path/**/SomeDir/path/*")

and that would match /path/to/your/SomeDir/path/file.

Answer 3

Check the result of p1.communicate()[0] . It maybe empty string.

. in "%s.*" % part_of_foldername seems to be the cause.

UPDATE

Found typo: comminucate -> comminucate

---

def get_tag(part_of_foldername):
    p1 = subprocess.Popen(["find", "/path/to/directory", "-maxdepth", "1", "-name", "*%s*" % part_of_foldername, "-type", "d"], stdout=subprocess.PIPE)
    out, err = p1.communicate()
    directory = out.split('\n')[0]
    p1.wait()
    if directory:
        os.chdir(directory)
        p2 = subprocess.Popen(["grep", "STUFF_", ".hgtags"], stdout=subprocess.PIPE)
        out, err = p2.communicate()
        p2.wait()
        return out.rstrip('\n')