Python opening multiple files

Python opening multiple files and using multiple directories at once

Normally, you would do this for one file: You could do the same with multiple files: Now, if you have N files, you could write your own context manager, but that would probably be an overkill. I chose izip_longest because it will continue to emit lines from both files, using None for the files that empty first, until all lines are consumed.

Python opening multiple files and using multiple directories at once

Your pseudocode ( for line in f and f1, x.write(line in f) y.write(line in f1) ) has the same effect as the original code you posted, and isn’t useful unless there is something about the corresponding lines in the two files that you want to process.

But you can use zip to combine iterables to get what you want

import itertools with open(os.path.join('./directory', filename1)) as r1, \ open(os.path.join('./directory2', filename1)) as r2, \ open(file1, 'a') as x, \ open(file2, 'a') as y: for r1_line, r2_line in itertools.izip_longest(r1, r2): if r1_line and "string" in line: x.write(r1_line) if r2_line and "string" in line: y.write(r1_line) 

• I put all of the file objects in a single with clause using \ to escape the new line so that python sees it as a single line
• The various permutations of zip combine iterables into a sequence of tuples.
• I chose izip_longest because it will continue to emit lines from both files, using None for the files that empty first, until all lines are consumed. if r1_line . just makes sure we aren’t at the Nones for file that has been fully consumed.
• This is a strange way to do things — for the example you’ve given, it’s not the better choice.

Execute multiple python files using a single main, As previous answers suggest, if you simply need to re-use the functionality do an import. However, if you do not know the file names in advance, you would need to use a slightly different import construct. For a file called one.py located in the same directory, use: Contents of the one.py: print «test» def print_a(): print «aa» Your …

Opening multiple files in Python before closing previous?

Seems legit and works fine.

Doing operations would be hard for you this way. the list «files» doesn’t contain the filenames. You would not know which file is what.

It is perfectly fine to open each file using open and later close all of them. However, you will want to make sure all of your files are closed properly.

Normally, you would do this for one file:

with open(filename,'w') as f: do_something_with_the_file(f) # the file is closed here, regardless of what happens # i.e. even in case of an exception 

You could do the same with multiple files:

with open(filename1,'w') as f1, open(filename2,'w') as f2: do_something_with_the_file(f) # both files are closed here 

Now, if you have N files, you could write your own context manager, but that would probably be an overkill. Instead, I would suggest:

open_files = [] try: for filename in list_of_filenames: open_files.append(open(filename, 'w')) # do something with the files here finally: for file in open_files: file.close() 

BTW, your own code deltes the contents of all files in the current directory. I am not sure you wanted that:

for file in os.listdir(os.curdir): files.append(open(file,'w')) # open(file,'w') empties the file. 

Maybe you wanted open(file, ‘r’) or open(file, ‘a’) instead? (see https://docs.python.org/2/library/functions.html#open)

Your solution will certainly work but the recommended way would be to use contextmanager so that the files gets handled seamlessly. For example

for filename in os.listdir(os.curdir): with open(filename, 'w') as f: # do some actions on the file 

The with statement will take care of closing the file for you.

How To Work With Multiple .py Files In One Project, import things from things import config things.printline (config) things.py. config = ‘This is a variable assignment’ def printline (line): print (line) return line. It’s really that easy. You can also store several files into a directory and just import the directory the same way, you just need to have an empty __init__.py …

Opening two files simultaneously on a «with» context [duplicate]

from pathlib import Path file1 = Path('file1.txt') file2 = Path('file2.txt') with file1.open() as f1, file2.open() as f2: '''do something with file handles. 

Documentation for with statement covers the case for multiple context expressions.

The correct one is with file1.open() as f1, file2.open() as f2:

Depending on what you want to do with f1 and f2 you can use directly pathlib.Path.read_text() and pathlib.Path.write_text() , e.g.

from pathlib import Path file1 = Path('file1.txt') content = file1.read_text() print(content) 

Python: Loop to open multiple folders and files in python, I am new to python and currently work on data analysis. I am trying to open multiple folders in a loop and read all files in folders. Ex. working directory contains 10 folders needed to open and each folder contains 10 files.

Reading two files in python

One way to fix, is move this line:

 data = open("idnum2itemdisplaynametable.txt", 'r') 

That way you re-open the data file as needed. (Adjust your exception handling as needed to close the data file. Consider using with .)

Secondly, to get a closer port to the PHP code you posted, you could use readlines . You are reading the file several times anyway, after all. Just read them all at once to start with and then do your processing.

So, leaving the data opening code where it is, you would do:

 data_f = open("idnum2itemdisplaynametable.txt", 'r') data = data_f.readlines() 

Then your for line2 in data loop is just revisiting an array of lines.

Well, I would do something like this for comparing two files:

def compare_two_files(filename1, filename2): input1 = open(filename1) input2 = open(filename2) lines1 = input1.readlines() lines2 = input2.readlines() # Iterate over the two files for l1 in lines1: cur_l1 = l1.split(',') for l2 in lines2: cur_l2 = l2.split(',') # Compare file's lines if cur_l1[0] == cur_l2[0]: print('something') 

I didn’t test it but it should works.

Python — Open multiple txt files in python3, import os all_txt_files = os.listdir (file_dir) for txt in all_txt_files: txt_dir = file_dir + txt with open (txt_dir, ‘r’) as txt_file: # read from a single Textfile whatever you want to. Note: Depending on your python version the Textfiles might not be sorted by os.listdir () prevent that by sorted (os.listdir ())

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Open & Read Multiple Files Simultaneously Using with Statement In Python.

We use files for future use of our data by permanently storing them on optical drives, hard drives, or other types of storage devices.

Since we store our data in the files, sometimes we need them to read, write, or see our data.

For such file operations, in Python, we have a built-in function, which can help in opening a file, performing reading and writing operations on a file, and even closing the file after the task is completed.

Introduction

In this article, we gonna discuss the ways how we can open multiple files using the with statement in Python?

Let’s explore the ways and write some code.

Using open() function

Well, the first way we gonna discuss is the use of Python’s in-built open() function.

If you are familiar with the open() function, then you might know that it takes only one file path at a time.

Here’s the syntax:

open(file, mode=’r’, buffering=- 1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

Hence, we cannot pass multiple files path and if we try to do so then we get an error.

But there is a way, we can use the with statement to open and read multiple files using the open() function.

Here’s the code:

• with open(«first.txt») as file_1, open(«second.txt») as file_2, open(«third.txt») as file_3 : Here, we used open() function for each file which is wrapped within with statement.
• f1 = file_1.read() f2 = file_2.read() f3 = file_3.read() : Then we used read() function and store them in the variable.
• for lines in f1, f2, f3 : We used the for loop to iterate over the contents, in each file.
• print(lines) : Then we finally print the contents of each file.

Here’s the output:

What if we have lots of files, which we have to open and read simultaneously, then we have to write more lines of code which in turn kinda gets messy, and it’s not a good practice.

Well, we have another way of doing the same operation with lesser lines of code.

Using fileinput Module

First of all, fileinput module is a built-in module in Python, so you don’t need to install it explicitly.

fileinput — Iterate over lines from multiple input streams

Using the open() function to open multiple files simultaneously can be good but it’s not convenient.

Instead of using the first way, we can use fileinput module.

Let’s dive into the code and learn the use case:

• import fileinput : Since it’s a module, we have to import it to get started.
• with fileinput.input(files=(‘first.txt’, ‘second.txt’,’third.txt’)) as f : We are calling here input method from fileinput module and specifying our files into it which we wrapped within with statement.
• for line in f : Here we are using for loop to iterate over the contents of our file.
• print(line) : Finally printing those content.

for more details about fileinput module Click here.

Here’s the output:

The output is the same because we used the same files which we used above.

Note: This module opens the file in read mode only, we cannot open the files in writing mode. It must be one of ‘r’ , ‘rU’ , ‘U’ , and ‘rb’ .

Conclusion

We carried out the same task but we used different approaches to handle them. Both ways are quite good.

We learned here two ways to deal with reading and opening multiple files. One is using the open() function and another was using the fileinput module.

But every function and module has its own pros and cons.

We can’t use Python’s open() function to open multiple files until and unless we use the with statement with it but if we have lots of files then the code will get kinda messy.

And for fileinput module, we get the same task done with lesser lines of code but it can be used for only read mode.

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Open Multiple Files Using with open in Python

To open multiple files in Python, you can use the standard with open() as name syntax and for each additional file you want to open, add a comma in between the with open statements.

with open("file1.txt","w") as f1, open("file2.txt","w") as f2: #do stuff here

When working with files in Python, the ability to open multiple files can sometimes be useful as you may need information from different files.

It is well known that you can use with open to open a file, read from it or write to it.

For opening multiple files, all you need to do is add a comma in between the with open blocks.

Below shows you an example of how you can open multiple files using with open in Python.

with open("file1.txt","w") as f1, open("file2.txt","w") as f2: #do stuff here

How to Open More than Two Files at Once in Python

If you want to open more than two files at once in Python, then you can take the example above and add to it.

As you saw above, you just need to put a comma in between the with open statements to open multiple files.

Therefore, if you want to open more than two files, then you would just add another file at the end of your line.

Below shows you how to open three files in Python using with open

with open("file1.txt","w") as f1, open("file2.txt","w") as f2, open("file3.txt", "w") as f3: #do stuff here

Hopefully this article has been useful for you to learn how to open multiple files in Python.

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