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Is there a way to use a retrieved file name as a variable?

I'm looking to retrieve a list of CSV files, and use these names as variables to open and retrieve their content. Something like this:
import csv
import os
files = os.listdir('C:/csvs')
with open(files[0], 'r') as csv_file:
csv_reader = csv.reader(csv_file)
for line in csv_reader:
if line[1]=="**STAFF**":
pass
else:
print(line)
If I print files[0], I do get the correct content, but when I try the above code it does not work.

os.listdir(directory_path) gives filenames which are inside the folder. To actually use the file you need the full path (absolute or relative). This can be easily done by appending each file's name to the directory_path like this:
import os
files = os.listdir(directory_path)
full_file_path = os.path.join(directory_path, files[0])
You can also use glob to save the trouble of joining the paths.

Unable to remove zipped file after unzipping

I'm attempting to remove a zipped file after unzipping the contents on windows. The contents can be stored in a folder structure in the zip. I'm using the with statement and thought this would close the file-like object (source var) and zip file. I've removed lines of code relating to saving the source file.
import zipfile
import os
zipped_file = r'D:\test.zip'
with zipfile.ZipFile(zipped_file) as zip_file:
for member in zip_file.namelist():
filename = os.path.basename(member)
if not filename:
continue
source = zip_file.open(member)
os.remove(zipped_file)
The error returned is:
WindowsError: [Error 32] The process cannot access the file because it is being used by another process: 'D:\\test.zip'
I've tried:
looping over the os.remove line in case it's a slight timing issue
Using close explicitly instead of the with statment
Attempted on local C drive and mapped D Drive

instead of passing in a string to the ZipFile constructor, you can pass it a file like object:
import zipfile
import os
zipped_file = r'D:\test.zip'
with open(zipped_file, mode="r") as file:
zip_file = zipfile.ZipFile(file)
for member in zip_file.namelist():
filename = os.path.basename(member)
if not filename:
continue
source = zip_file.open(member)
os.remove(zipped_file)

You are opening files inside the zip... which create a file lock on the whole zip file. close the inner file open first... via source.close() at the end of your loop
import zipfile
import os
zipped_file = r'D:\test.zip'
with zipfile.ZipFile(zipped_file) as zip_file:
for member in zip_file.namelist():
filename = os.path.basename(member)
if not filename:
continue
source = zip_file.open(member)
source.close()
os.remove(zipped_file)

Try to close the zipfile before removing.

you can do also like this, which works pretty good:
import os, shutil, zipfile
fpath= 'C:/Users/dest_folder'
path = os.getcwd()
for file in os.listdir(path):
if file.endswith(".zip"):
dirs = os.path.join(path, file)
if os.path.exists(fpath):
shutil.rmtree(fpath)
_ = os.mkdir(fpath)
with open(dirs, 'rb') as fileobj:
z = zipfile.ZipFile(fileobj)
z.extractall(fpath)
z.close()
os.remove(dirs)

Python file-IO and zipfile. Trying to loop through all the files in a folder and then loop through the texts in respective file using Python

Trying to extract all the zip files and giving the same name to the folder where all the files are gonna be.
Looping through all the files in the folder and then looping through the lines within those files to write on a different text file.
This is my code so far:
#!usr/bin/env python3
import glob
import os
import zipfile
zip_files = glob.glob('*.zip')
for zip_filename in zip_files:
dir_name = os.path.splitext(zip_filename)[0]
os.mkdir(dir_name)
zip_handler = zipfile.ZipFile(zip_filename, "r")
zip_handler.extractall(dir_name)
path = dir_name
fOut = open("Output.txt", "w")
for filename in os.listdir(path):
for line in filename.read().splitlines():
print(line)
fOut.write(line + "\n")
fOut.close()
This is the error that I encounter:
for line in filename.read().splitlines():
AttributeError: 'str' object has no attribute 'read'

You need to open the file and also join the path to the file, also using splitlines and then adding a newline to each line is a bit redundant:
path = dir_name
with open("Output.txt", "w") as fOut:
for filename in os.listdir(path):
# join filename to path to avoid file not being found
with open(os.path.join(path, filename)):
for line in filename:
fOut.write(line)
You should always use with to open your files as it will close them automatically. If the files are not large you can simply fOut.write(f.read()) and remove the loop.
You also set path = dir_name which means path will be set to whatever the last value of dir_name was in your first loop which may or may not be what you want. You can also use iglob to avoid creating a full list zip_files = glob.iglob('*.zip').

Reading/Writing Text from Multiple Files to Master File

In the code below I'm trying to open a series of text files and copy their contents into a single file. I'm getting an error on the "os.write(out_file, line)" in which it asks me for an integer. I haven't defined what "line" is, so is that the problem? Do I need to specify somehow that "line" is a text string from the in_file? Also, I open the out_file through each iteration of the for-loop. Is that bad? Should I open it once at the beginning? Thanks!
import os
import os.path
import shutil
# This is supposed to read through all the text files in a folder and
# copy the text inside to a master file.
# This defines the master file and gets the source directory
# for reading/writing the files in that directory to the master file.
src_dir = r'D:\Term Search'
out_file = r'D:\master.txt'
files = [(path, f) for path,_,file_list in os.walk(src_dir) for f in file_list]
# This for-loop should open each of the files in the source directory, write
# their content to the master file, and finally close the in_file.
for path, f_name in files:
open(out_file, 'a+')
in_file = open('%s/%s' % (path, f_name), 'r')
for line in in_file:
os.write(out_file, line)
close(file_name)
close(out_file)
print 'Finished'

You're doing it wrong:
You did:
open(out_file, 'a+')
but that doesn't save the reference as a variable, so you have no way to access the file object you just created. What you need to do:
out_file_handle = open(out_file, 'a+')
...
out_file_handle.write(line)
...
out_file_handle.close()
Or, more pythonically:
out_filename = r"D:\master.txt"
...
with open(out_filename, 'a+') as outfile:
for filepath in files:
with open(os.path.join(*filepath)) as infile:
outfile.write(infile.read())
print "finished"

How to read and write multiple files?

I want to write a program for this: In a folder I have n number of files; first read one file and perform some operation then store result in a separate file. Then read 2nd file, perform operation again and save result in new 2nd file. Do the same procedure for n number of files. The program reads all files one by one and stores results of each file separately. Please give examples how I can do it.

I think what you miss is how to retrieve all the files in that directory.
To do so, use the glob module.
Here is an example which will duplicate all the files with extension *.txt to files with extension *.out
import glob
list_of_files = glob.glob('./*.txt') # create the list of file
for file_name in list_of_files:
FI = open(file_name, 'r')
FO = open(file_name.replace('txt', 'out'), 'w')
for line in FI:
FO.write(line)
FI.close()
FO.close()

import sys
# argv is your commandline arguments, argv[0] is your program name, so skip it
for n in sys.argv[1:]:
print(n) #print out the filename we are currently processing
input = open(n, "r")
output = open(n + ".out", "w")
# do some processing
input.close()
output.close()
Then call it like:
./foo.py bar.txt baz.txt

You may find the fileinput module useful. It is designed for exactly this problem.

I've just learned of the os.walk() command recently, and it may help you here.
It allows you to walk down a directory tree structure.
import os
OUTPUT_DIR = 'C:\\RESULTS'
for path, dirs, files in os.walk('.'):
for file in files:
read_f = open(os.join(path,file),'r')
write_f = open(os.path.join(OUTPUT_DIR,file))
# Do stuff

Combined answer incorporating directory or specific list of filenames arguments:
import sys
import os.path
import glob
def processFile(filename):
fileHandle = open(filename, "r")
for line in fileHandle:
# do some processing
pass
fileHandle.close()
def outputResults(filename):
output_filemask = "out"
fileHandle = open("%s.%s" % (filename, output_filemask), "w")
# do some processing
fileHandle.write('processed\n')
fileHandle.close()
def processFiles(args):
input_filemask = "log"
directory = args[1]
if os.path.isdir(directory):
print "processing a directory"
list_of_files = glob.glob('%s/*.%s' % (directory, input_filemask))
else:
print "processing a list of files"
list_of_files = sys.argv[1:]
for file_name in list_of_files:
print file_name
processFile(file_name)
outputResults(file_name)
if __name__ == '__main__':
if (len(sys.argv) > 1):
processFiles(sys.argv)
else:
print 'usage message'

from pylab import *
import csv
import os
import glob
import re
x=[]
y=[]
f=open("one.txt",'w')
for infile in glob.glob(('*.csv')):
# print "" +infile
csv23=csv2rec(""+infile,'rb',delimiter=',')
for line in csv23:
x.append(line[1])
# print len(x)
for i in range(3000,8000):
y.append(x[i])
print ""+infile,"\t",mean(y)
print >>f,""+infile,"\t\t",mean(y)
del y[:len(y)]
del x[:len(x)]

I know I saw this double with open() somewhere but couldn't remember where. So I built a small example in case someone needs.
""" A module to clean code(js, py, json or whatever) files saved as .txt files to
be used in HTML code blocks. """
from os import listdir
from os.path import abspath, dirname, splitext
from re import sub, MULTILINE
def cleanForHTML():
""" This function will search a directory text files to be edited. """
## define some regex for our search and replace. We are looking for <, > and &
## To replaced with &ls;, > and &. We might want to replace proper whitespace
## chars to as well? (r'\t', ' ') and (f'\n', '<br>')
search_ = ((r'(<)', '<'), (r'(>)', '>'), (r'(&)', '&'))
## Read and loop our file location. Our location is the same one that our python file is in.
for loc in listdir(abspath(dirname(__file__))):
## Here we split our filename into it's parts ('fileName', '.txt')
name = splitext(loc)
if name[1] == '.txt':
## we found our .txt file so we can start file operations.
with open(loc, 'r') as file_1, open(f'{name[0]}(fixed){name[1]}', 'w') as file_2:
## read our first file
retFile = file_1.read()
## find and replace some text.
for find_ in search_:
retFile = sub(find_[0], find_[1], retFile, 0, MULTILINE)
## finally we can write to our newly created text file.
file_2.write(retFile)

This thing also works for reading multiple files, my file name is fedaralist_1.txt and federalist_2.txt and like this, I have 84 files till fedaralist_84.txt
And I'm reading the files as f.
for file in filename:
with open(f'federalist_{file}.txt','r') as f:
f.read()