subprocess - Unable to loop the files to perform diff in python -

i new python. writing python script find diff between 2 html file1: beta.vidup.me-log-2016-09-21-17:43:28.html , file2: beta.vidup.me-log-2016-09-21-17:47:48.html.

to give idea file organization: have 2 directories 2016-09-21 , 2016-09-22. file1: beta.vidup.me-log-2016-09-21-17:43:28.html present in dir1 , file2: beta.vidup.me-log-2016-09-21-17:47:48.html present in dir2.

below snippet:

dir1 = raw_input("enter date of archive folder compare in format yyyy-mm-dd---->\n") dir2 = raw_input("enter date of folder compare in format yyyy-mm-dd----->\n")  = datetime.now() folder_output = '/home/diff_output/{}'.format(now.strftime('%y-%m-%d'))  mkdir(folder_output)  fname1 = '/home/output/%s/beta.vidup.me-log-2016-09-21-17:43:28.html'%dir1 fname2 = '/home/output/%s/beta.vidup.me-log-2016-09-21-17:47:48.html'%dir2  # open file reading in text mode (default mode) f1 = open(fname1) f2 = open(fname2)  cmd = "diff "+fname1+'\t'+fname2 curl = subprocess.popen(cmd,shell=true,stdout=subprocess.pipe)  file_data = curl.stdout.read() print file_data  fname1.close() fname2.close() 

i wish perform diff using subprocess module only.

i want code take fname1 dir1 , fname2 dir2 , perform diff , output folder , loop pick next file in dir1 fname1 , next file dir2 fname2 , perform diff again.

thanks time , advice in advance.

below functions need examples. merge them using logic for loop.

you can use subprocess.check_output() output command. try:

cmd = ["diff", fname1, +fname2] output = subprocess.check_output(cmd) print output 

if want write file:

with open('/paht/to/file', 'w+') f:     f.write(output) 

in order list of files in directory, use listdir(), isfile , join functions of os module. example:

from os import listdir os.path import isfile, join only_files = [f f in listdir('path') if isfile(join('path', f))] # only_files contain list of files in 'path' path 

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as mentioned, don't have idea on loop. give basic idea on how loop should work. below example (instead of copying, try understand each line. it'll helpful in future):

for f1, f2 in zip(file_list_1, file_list_2): # takes first, second, etc files corresponding each list      output = subprocess.check_output(['diff', f1, f2]) # generate diff of both file     open('diff-{}-{}'.format(f1, f2), 'w+') f:         f.write(output)  # write diff third file 

modify above logic per requirement.