open multiple files in python using loop - python

you can write any code you like.There are three files loaded and ready for you to open if you want to do file processing "mbox-short.txt", "romeo.txt", and "words.txt".

What have you tried until now? You could may be use something like the following to store the file descriptors
files = ["mbox-short.txt", "romeo.txt", "words.txt"]
fileDescriptors = []
for fileName in files:
f = open(fileName, "r") #change r to rb if it is a binary file
fileDescriptors.append(f)
#do whatever you want with the file descriptors in the list

I recommend reading how to operate files in python first:
https://www.w3schools.com/python/python_file_open.asp
Here is an example snippet:
filenames = ["a.txt", "b.txt", "c.txt"]
opened_files = []
for filename in filenames:
opened_files.append(open(filename, "r"))
# Do whatever you need with file objects
# Eg:
print(opened_files[1].read())

Related

Get only the txt file you want from the folder containing the txt file - Python

I have a folder with a .txt files. the name of the files are:
my_file1.txt
my_file2.txt
my_file3.txt
my_file4.txt
In this way, only the last number is different.
import pickle
my_list = []
with open("/Users/users_a/Desktop/website-basic/sub_domain/sub_domain01.txt", "rb") as f1,
open("/Users/users_a/Desktop/website-ba\
sic/sub_domain/sub_domain02.txt", "rb") as f2, open("/Users/users_a/Desktop/website-
basic/sub_domain/sub_domain03.txt", "rb") as f3:
my_list.append(pickle.load(f1))
my_list.append(pickle.load(f2))
my_list.append(pickle.load(f3))
print(my_list)
In this way, I load a file and put it in the my_list variable to make a list and work. As the number of files to work increases, the code becomes too long and cumbersome.
Is there an easier and more pythonic way to load only the desired txt file??
You can use os.listdir():
import os
import pickle
my_list = []
path = "/Users/users_a/Desktop/website-basic/sub_domain"
for file in os.listdir(path):
if file.endswith(".txt"):
with open(f"{path}/{file}","r") as f:
my_list.append(pickle.load(f))
Where file is the filename of a file in path
I suggest using os.path.join() instead of hard coding the file paths
If your folder only contains the files you want to load you can just use:
for file in os.listdir(path):
with open(f"{path}/{file}","r") as f:
my_list.append(pickle.load(f))
Edit for my_file[number].txt
If you only want files in the form of my_file[number].txt, use:
import os
import re
import pickle
my_list = []
path = "/Users/users_a/Desktop/website-basic/sub_domain"
for file in os.listdir(path):
if re.match(r"my_file\d+.txt", file):
with open(f"{path}/{file}","r") as f:
my_list.append(pickle.load(f))
Online regex demo https://regex101.com/r/XJb2DF/1

Find files that had been stored from a single text file

Is there any way for me to read file that I saved inside a text file using python?
For example I have a file called filenames.txt. The content of the file should have name of other files such as:
/home/ikhwan/acespc.c
/home/ikhwan/trloc.cpp
/home/ikhwan/Makefile.sh
/home/ikhwan/Readme.txt
So, theoretically what I want to do is I have a Python script to change some header of the file. So filenames.txt will act as a platform for me whenever I want to run the script to change only selected file. The reason is I have so many files inside directory and subdirectories and I just want python to read only the files that I put inside filenames.txt and only change that particular file. In the future, if I want to run the script on other files, I just can add or replace filenames in filenames.txt
So the flow of the script will be as follows:
Run script-->script start search for the filenames inside filenames.txt-->script will add or change header of the file.
Current, i used os.walk but it will search within all directory and subdirectory. Here are my current function.
def read_file(file):
skip = 0
headStart = None
headEnd = None
yearsLine = None
haveLicense = False
extension = os.path.splitext(file)[1]
logging.debug("File extension is %s",extension)
type = ext2type.get(extension)
logging.debug("Type for this file is %s",type)
if not type:
return None
settings = typeSettings.get(type)
with open(file,'r') as f:
lines = f.readlines()
You don't need to walk through the file system if you already have your file paths listed in the filenames.txt, just open it, read it line by line and then process each file path from it, e.g.
# this is your method that will be called with each file path from the filenames.txt
def process_file(path):
# do whatever you want with `path` in terms of processing
# let's just print it to STDOUT as an example
with open(path, "r") as f:
print(f.read())
with open("filenames.txt", "r") as f: # open filenames.txt for reading
for line in f: # read filenames.txt line by line
process_file(line.rstrip()) # send the path stored on the line to process_file()

Printing content of all files in directory

I am trying to go to a directory and print out the content of all files in it.
for fn in os.listdir('Z:/HAR_File_Generator/HARS/job_search'):
print(fn)
When I use this code all it does is print out the file names. How can I make it so I can actually get the content of the file? I have seen a lot of ways to possibly do this but I am wondering if there is a way to do it in the same format as I have it. It doesn't make sense to me that I'm not able to get the file content instead of the name. What would make sense to me is doing fn.read() and then printing it out but that does not work.
directory = 'Z:/HAR_File_Generator/HARS/job_search'
for fn in os.listdir(directory):
print(open(os.path.join(directory, fn), 'rb').read())
Edit: You should probably close your files too but that's a separate issue.
mydir = 'Z:/HAR_File_Generator/HARS/job_search'
for fn in os.listdir(mydir):
print open(mydir+'/'+fn).readlines()
Why is your code not printing any file contents? Because you are not reading any file contents.
For printing prettily..
for fn in os.listdir(mydir):
for line in open(mydir+'/'+fn).readlines():
print line
And to avoid this closing issue in case of much much larger files,
for fn in os.listdir(mydir):
with open(mydir+'/'+fn) as fil:
print fil.readlines()
Assuming they're text files that can actually be printed:
dirpath = 'Z:/HAR_File_Generator/HARS/job_search'
for fn in os.listdir(dirpath):
with open(os.path.join(dirpath, fn), 'r') as f: # open the file
for line in f: # go through each line
print(line) # and print it
Or, in Python 3 (or Python 2 with the proper import):
dirpath = 'Z:/HAR_File_Generator/HARS/job_search'
for fn in os.listdir(dirpath):
with open(os.path.join(dirpath, fn), 'r') as f: # open the file
print(*f, sep='') # and send every line to the print function

Reading files of same typolgy in a folder

I need a little help to finish my program.
I have in a folder 20 files of the same typology, strings with corresponding values.
Is there a way to create a function that opens all the files in this way
file1 = [line.strip() for line in open("/Python34/elez/file1.txt", "r")]?
I hope I explained it well.
Thanks!
from os import listdir
from os.path import join, isfile
def contents(filepath):
with open(filepath) as f:
return f.read()
directory = '/Python34/elez'
all_file_contents = [contents(join(directory, filename))
for filename in listdir(directory)
if isfile(join(directory, filename)]
Hi Gulliver this is how i will do it:
import os
all_files = [] ## create a list to keep all the lines for all files
for file in os.listdir('./'): ## use list dir to list all files in the dir
with open(file, 'r') as f: ## use with to open file
fields = [line.strip() for line in f] ## list comprehension to finish reading the field
all_fields.extend(fields) ## store in big list
For more information about using the with statement to open and read files, please refer to this answer Correct way to write to files?

Iterating files with os.walk, but cannot open and print text files

Currently I am trying to write a function will walk through the requested directory and print all the text of all the files.
Right now, the function works in displaying the file_names as a list so the files surely exist (and there is text in the files).
def PopularWordWalk (starting_dir, word_dict):
print ("In", os.path.abspath(starting_dir))
os.chdir(os.path.abspath(starting_dir))
for (this_dir,dir_names,file_names) in os.walk(starting_dir):
for file_name in file_names:
fpath = os.path.join(os.path.abspath(starting_dir), file_name)
fileobj = open(fpath, 'r')
text = fileobj.read()
print(text)
Here is my output with some checking of the directory contents:
>>> PopularWordWalk ('text_dir', word_dict)
In /Users/normanwei/Documents/Python for Programmers/Homework 4/text_dir
>>> os.listdir()
['.DS_Store', 'cats.txt', 'zen_story.txt']
the problem is that whenever i try to print the text, i get nothing. eventually I want to push the text through some other functions but as of now it seems moot without any text. Can anyone lend any experience on why no text is appearing? (when trying to open files/read/storing&printing text manually in idle it works i.e. if I just manually inputted 'cats.txt' instead of 'file_name') - currently running python 3.
EDIT - The question has been answered - just have to remove the os.chdir line - see jojo's answer for explanation.
This line won't work
file = open(file_name, 'r')
Because it would require that these files exist in the same folder you are running the script from. You would have to provide the path to those files, as well as the file names
with open(os.path.join(starting_dir,file_name), 'r') as file:
#do stuff
This way it will build the full path from the directory and the file name.
If you do os.chdir(os.path.abspath(starting_dir)) you go into starting_dir. Then for (this_dir,dir_names,file_names) in os.walk(starting_dir): will loop over nothing since starting_dir is not in starting_dir.
Long story short, comment the line os.chdir(os.path.abspath(starting_dir)) and you should be good.
Alternatively if you want to stick to the os.chdir, this should do the job:
def PopularWordWalk (starting_dir, word_dict):
print ("In", os.path.abspath(starting_dir))
os.chdir(os.path.abspath(starting_dir))
for (this_dir,dir_names,file_names) in os.walk('.'):
for file_name in file_names:
fpath = os.path.join(os.path.abspath(starting_dir), file_name)
with open(fpath, 'r') as fileobj:
text = fileobj.read()
print(text)
You'll want to join the root path with the file path. I'd change:
file = open(file_name, 'r')
to
fpath = os.path.join(this_dir, file_name)
file = open(fpath, 'r')
You may also want to use another word to describe it than file as that's a built-in function in Python. I'd recommend fileobj.
Just to add on to the previous answer, you will have to join the absolute path and the relative path of the walk.
Try this:
fpath = os.path.abspath(os.path.join(this_dir, file_name))
f = open(fpath, 'r')

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