How to use os.walk to only list text files - python

This question was similar in addressing hidden filetypes. I am struggling with a similar problem because I need to process only text containing files in folders that have many different filetypes- pictures, text, music. I am using os.walk which lists EVERYTHING, including files without an extension-like Icon files. I am using linux and would be satisfied to filter for only txt files. One way is too check the filename extension and this post explains nicely how it's done.
But this still leaves mislabeled files or files without an extension. There are hex values that uniquely identify filetypes known as magic numbers or file signatures. here and here Unfortunately, magic numbers do not exist for text files (see here).
One strategy that I have come up with is to parse the first bunch of characters to make sure they are words by doing a dictionary lookup(I am only dealing with English texts) Then only proceed with the full text processing if that is true.This approach seems rather heavy and expensive (doing a bunch of dictionary lookups for each file). Another approach is simply to look for the word 'the' which is unlikely to be frequent in a data file but commonly found in text files. But false negatives would cause me to lose text files for processing. I tried asking google for the longest text without the word 'the' but had no luck with that.
I do not know if this is the appropriate forum for this kind of question-it's almost a question of AI rather than computer science/coding. It's not as difficult as gibberish detection. The texts may not be semantically or syntactically correct- they might just be words like the inventory of a stockroom but also they might be prose and poetry. I just do not want to process files that could be byte code,source code, or collections of alphanumeric characters that are not English words.

You can use Python's mimetypes library to check whether a file is a plaintext file.
import os
import mimetypes
for dirpath, dirnames, filenames in os.walk('/path/to/directory'):
for filename in filenames:
if mimetypes.guess_type(filename)[0] == 'text/plain':
print(os.path.join(dirpath, filename))
UPDATE: Since the mimetypes library uses file extension to determine the type of file, it is not very reliable, especially since you mentioned that some files are mislabeled or without extensions.
For those cases you can use the magic library (which is not in the standard library unfortunately).
import os
import magic
mime = magic.Magic(mime=True)
for dirpath, dirnames, filenames in os.walk('/path/to/directory'):
for filename in filenames:
fullpath = os.path.join(dirpath, filename)
if mime.from_file(fullpath) == 'text/plain':
print(fullpath)
UPDATE 2: The above solution wouldn't catch files you would otherwise consider "plaintext" (e.g. XML files, source files, etc). The following solution should work in those cases:
import os
import magic
for dirpath, dirnames, filenames in os.walk('/path/to/directory'):
for filename in filenames:
fullpath = os.path.join(dirpath, filename)
if 'text' in magic.from_file(fullpath):
print(fullpath)
Let me know if any of these works for you.

A pretty good heuristic is to look for null bytes at the beginning of the file. Text files don't typically have them and binary files usually have lots of them. Below checks that the first 1K bytes contain no nulls. You can of course adjust how much or little of the file to read:
#!python3
import os
def textfiles(root):
for path,dirs,files in os.walk(root):
for file in files:
fullname = os.path.join(path,file)
with open(fullname,'rb') as f:
data = f.read(1024)
if not 0 in data:
yield fullname
for file in textfiles('.'):
print(file)

Related

How to check whether file name contains a specific character with Pathlib

Since it looks like Pathlib is the future, I'm trying to refactor some of my code to change from from previous use of os to Pathlib. I'm stuck with the following problem. Since I work with a Mac, sometimes the folders contain hidden files preceded by a period (.DS_Store or names from deleted files preceded by ._). That gets me into a lot of problems when I loop through files in a directory that have certain extension. To avoid this problem using os.walk, I do the following:
for root, dirs, files in os.walk(DIR_NAME):
# iterate all files
for file in files:
if file.endswith(ext):
if file.startswith("."):
continue
do something with the file
I know we have the .stem and .suffix method to manipulate file names with Pathlib, but I don't see how they can help with this problem. The .startswith seems more intuitive but alas it does not seem to be available in Pathlib. So, the question is, how would one go about doing this in Pathlib?

How to load data set having multiple 'No-extension files' in python?

I am trying to load a dataset for my machine learning project and it requires me to load files having no extensions.
I tried :
import os
import glob
files = filter(os.path.isfile, glob.glob("./[0-9]*"))
for name in files:
with open(name) as fh:
contents = fh.read()
But doesn't return anything, mainly that glob command has nothing in it.
Also tried :
import os
import glob
path = './dataset1/training_validation/2012-07-10/'
for infile in glob.glob(os.path.join(path, '*')):
print("test")
file = open(infile, 'r')
print(file)
but this returns [] because of that glob command.
I'm stuck in here and couldn't find anything over the internet.
My actual problem is to load 'no extension files in a training and testing set' from two folders, validation, and the test itself. I can iterate through the folder but don't know how to handle those file types.
When I open those files in a text editor. it shows me something like this.
So I know that it's a binary format of an image, but have no idea how can I store and train them.
any help would be appreciated. thanks.
Two things:
File extensions (.txt , .dat , .bat, .f90, etc.) are not meaningful to python, at least when using glob or numpy or something of the sort, because it's just part of a string. Some of us are raised (within Windows) to believe that file extensions mean something (I too fell for it).
The file you are looking at is a text file, containing the ASCII representation of a binary image on 0's and 1's. So, it's not a binary file, and it's not an image file (per-se), but it is a text file, which means we can read it as such from python.
To read this in, you could do either:
1. Use numpy to do data = numpy.loadtxt(<filename>), however you might have trouble delimiting the digits.
2. Use Python's standard open function on the file, and loop through each line using for line in <file_handle>:. This way, each row of data is a string, which can be parsed easily (see documentation on string indexing).
Good luck!
IMO this simply means that your path does not exist.
Perhaps you try in a first test an absolute path to your folder, as you eventually confused the relative position of the folder to your current working directory.
I got it to work with the following code.
fileNames = [f for f in listdir(dirName) if isfile(join(dirName, f))]
random.shuffle(fileNames)
for files in fileNames:
data = open(dirName+'/'+files,'r');
Thanks for your responses.

Errors with Glob while outputting file names

I am combining two questions here because they are related to each other.
Question 1: I am trying to use glob to open all the files in a folder but it is giving me "Syntax Error". I am using Python 3.xx. Has the syntax changed for Python 3.xx?
Error Message:
File "multiple_files.py", line 29
files = glob.glob(/src/xyz/rte/folder/)
SyntaxError: invalid syntax
Code:
import csv
import os
import glob
from pandas import DataFrame, read_csv
#extracting
files = glob.glob(/src/xyz/rte/folder/)
for fle in files:
with open (fle) as f:
print("output" + fle)
f_read.close()
Question 2: I want to read input files, append "output" to the names and print out the names of the files. How can I do that?
Example: Input file name would be - xyz.csv and the code should print output_xyz.csv .
Your help is appreciated.
Your first problem is that strings, including pathnames, need to be in quotes. This:
files = glob.glob(/src/xyz/rte/folder/)
… is trying to divide a bunch of variables together, but the leftmost and rightmost divisions are missing operands, so you've confused the parser. What you want is this:
files = glob.glob('/src/xyz/rte/folder/')
Your next problem is that this glob pattern doesn't have any globs in it, so the only thing it's going to match is the directory itself.
That's perfectly legal, but kind of useless.
And then you try to open each match as a text file. Which you can't do with a directory, hence the IsADirectoryError.
The answer here is less obvious, because it's not clear what you want.
Maybe you just wanted all of the files in that directory? In that case, you don't want glob.glob, you want listdir (or maybe scandir): os.listdir('/src/xyz/rte/folder/').
Maybe you wanted all of the files in that directory or any of its subdirectories? In that case, you could do it with rglob, but os.walk is probably clearer.
Maybe you did want all the files in that directory that match some pattern, so glob.glob is right—but in that case, you need to specify what that pattern is. For example, if you wanted all .csv files, that would be glob.glob('/src/xyz/rte/folder/*.csv').
Finally, you say "I want to read input files, append "output" to the names and print out the names of the files". Why do you want to read the files if you're not doing anything with the contents? You can do that, of course, but it seems pretty wasteful. If you just want to print out the filenames with output appended, that's easy:
for filename in os.listdir('/src/xyz/rte/folder/'):
print('output'+filename)
This works in http://pyfiddle.io:
Doku: https://docs.python.org/3/library/glob.html
import csv
import os
import glob
# create some files
for n in ["a","b","c","d"]:
with open('{}.txt'.format(n),"w") as f:
f.write(n)
print("\nFiles before")
# get all files
files = glob.glob("./*.*")
for fle in files:
print(fle) # print file
path,fileName = os.path.split(fle) # split name from path
# open file for read and second one for write with modified name
with open (fle) as f,open('{}{}output_{}'.format(path,os.sep, fileName),"w") as w:
content = f.read() # read all
w.write(content.upper()) # write all modified
# check files afterwards
print("\nFiles after")
files = glob.glob("./*.*") # pattern for all files
for fle in files:
print(fle)
Output:
Files before
./d.txt
./main.py
./c.txt
./b.txt
./a.txt
Files after
./d.txt
./output_c.txt
./output_d.txt
./main.py
./output_main.py
./c.txt
./b.txt
./output_b.txt
./a.txt
./output_a.txt
I am on windows and would use os.walk (Doku) instead.
for d,subdirs,files in os.walk("./"): # deconstruct returned aktDir, all subdirs, files
print("AktDir:", d)
print("Subdirs:", subdirs)
print("Files:", files)
Output:
AktDir: ./
Subdirs: []
Files: ['d.txt', 'output_c.txt', 'output_d.txt', 'main.py', 'output_main.py',
'c.txt', 'b.txt', 'output_b.txt', 'a.txt', 'output_a.txt']
It also recurses into subdirs.

handling Unicode filenames in Python 3.4 on Windows

I'm trying to find a reliable way to scan files on Windows in Python, while allowing for the possibility that there may be various Unicode code points in the filenames. I've seen several proposed solutions to this problem, but none of them work for all of the actual issues that I've encountered in scanning filenames created by real-world software and users.
The code sample below is an attempt to extricate and demonstrate the core issue. It creates three files in a subfolder with the sorts of variations I've encountered, and then attempts to scan through that folder and display each filename followed by the file's contents. It will crash on the attempt to read the third test file, with OSError [Errno 22] Invalid argument.
import os
# create files in .\temp that demonstrate various issues encountered in the wild
tempfolder = os.getcwd() + '\\temp'
if not os.path.exists(tempfolder):
os.makedirs(tempfolder)
print('file contents', file=open('temp/simple.txt','w'))
print('file contents', file=open('temp/with a ® symbol.txt','w'))
print('file contents', file=open('temp/with these chars ΣΑΠΦΩ.txt','w'))
# goal is to scan the files in a manner that allows for printing
# the filename as well as opening/reading the file ...
for root,dirs,files in os.walk(tempfolder.encode('UTF-8')):
for filename in files:
fullname = os.path.join(tempfolder.encode('UTF-8'), filename)
print(fullname)
print(open(fullname,'r').read())
As it says in the code, I just want to be able to display the filenames and open/read the files. Regarding display of the filename, I don't care whether the Unicode characters are rendered correctly for the special cases. I just want to print the filename in a manner that uniquely identifies which file is being processed, and doesn't throw an error for these unusual sorts of filenames.
If you comment out the final line of code, the approach shown here will display all three filenames with no errors. But it won't open the file with miscellaneous Unicode in the name.
Is there a single approach that will reliably display/open all three of these filename variations in Python? I'm hoping there is, and my limited grasp of Unicode subtleties is preventing me from seeing it.
The following works fine, if you save the file in the declared encoding, and if you use an IDE or terminal encoding that supports the characters being displayed. Note that this does not have to be UTF-8. The declaration at the top of the file is the encoding of the source file only.
#coding:utf8
import os
# create files in .\temp that demonstrate various issues encountered in the wild
tempfolder = os.path.join(os.getcwd(),'temp')
if not os.path.exists(tempfolder):
os.makedirs(tempfolder)
print('file contents', file=open('temp/simple.txt','w'))
print('file contents', file=open('temp/with a ® symbol.txt','w'))
print('file contents', file=open('temp/with these chars ΣΑΠΦΩ.txt','w'))
# goal is to scan the files in a manner that allows for printing
# the filename as well as opening/reading the file ...
for root,dirs,files in os.walk(tempfolder):
for filename in files:
fullname = os.path.join(tempfolder, filename)
print(fullname)
print(open(fullname,'r').read())
Output:
c:\\temp\simple.txt
file contents
c:\temp\with a ® symbol.txt
file contents
c:\temp\with these chars ΣΑΠΦΩ.txt
file contents
If you use a terminal that does not support encoding the characters used in the filename, You will get UnicodeEncodeError. Change:
print(fullname)
to:
print(ascii(fullname))
and you will see that the filename was read correctly, but just couldn't print one or more symbols in the terminal encoding:
'C:\\temp\\simple.txt'
file contents
'C:\\temp\\with a \xae symbol.txt'
file contents
'C:\\temp\\with these chars \u03a3\u0391\u03a0\u03a6\u03a9.txt'
file contents

taking data from files which are in folder

How do I get the data from multiple txt files that placed in a specific folder. I started with this could not fix. It gives an error like 'No such file or directory: '.idea' (??)
(Let's say I have an A folder and in that, there are x.txt, y.txt, z.txt and so on. I am trying to get and print the information from all the files x,y,z)
def find_get(folder):
for file in os.listdir(folder):
f = open(file, 'r')
for data in open(file, 'r'):
print data
find_get('filex')
Thanks.
If you just want to print each line:
import glob
import os
def find_get(path):
for f in glob.glob(os.path.join(path,"*.txt")):
with open(os.path.join(path, f)) as data:
for line in data:
print(line)
glob will find only your .txt files in the specified path.
Your error comes from not joining the path to the filename, unless the file was in the same directory you were running the code from python would not be able to find the file without the full path. Another issue is you seem to have a directory .idea which would also give you an error when trying to open it as a file. This also presumes you actually have permissions to read the files in the directory.
If your files were larger I would avoid reading all into memory and/or storing the full content.
First of all make sure you add the folder name to the file name, so you can find the file relative to where the script is executed.
To do so you want to use os.path.join, which as it's name suggests - joins paths. So, using a generator:
def find_get(folder):
for filename in os.listdir(folder):
relative_file_path = os.path.join(folder, filename)
with open(relative_file_path) as f:
# read() gives the entire data from the file
yield f.read()
# this consumes the generator to a list
files_data = list(find_get('filex'))
See what we got in the list that consumed the generator:
print files_data
It may be more convenient to produce tuples which can be used to construct a dict:
def find_get(folder):
for filename in os.listdir(folder):
relative_file_path = os.path.join(folder, filename)
with open(relative_file_path) as f:
# read() gives the entire data from the file
yield (relative_file_path, f.read(), )
# this consumes the generator to a list
files_data = dict(find_get('filex'))
You will now have a mapping from the file's name to it's content.
Also, take a look at the answer by #Padraic Cunningham . He brought up the glob module which is suitable in this case.
The error you're facing is simple: listdir returns filenames, not full pathnames. To turn them into pathnames you can access from your current working directory, you have to join them to the directory path:
for filename in os.listdir(directory):
pathname = os.path.join(directory, filename)
with open(pathname) as f:
# do stuff
So, in your case, there's a file named .idea in the folder directory, but you're trying to open a file named .idea in the current working directory, and there is no such file.
There are at least four other potential problems with your code that you also need to think about and possibly fix after this one:
You don't handle errors. There are many very common reasons you may not be able to open and read a file--it may be a directory, you may not have read access, it may be exclusively locked, it may have been moved since your listdir, etc. And those aren't logic errors in your code or user errors in specifying the wrong directory, they're part of the normal flow of events, so your code should handle them, not just die. Which means you need a try statement.
You don't do anything with the files but print out every line. Basically, this is like running cat folder/* from the shell. Is that what you want? If not, you have to figure out what you want and write the corresponding code.
You open the same file twice in a row, without closing in between. At best this is wasteful, at worst it will mean your code doesn't run on any system where opens are exclusive by default. (Are there such systems? Unless you know the answer to that is "no", you should assume there are.)
You don't close your files. Sure, the garbage collector will get to them eventually--and if you're using CPython and know how it works, you can even prove the maximum number of open file handles that your code can accumulate is fixed and pretty small. But why rely on that? Just use a with statement, or call close.
However, none of those problems are related to your current error. So, while you have to fix them too, don't expect fixing one of them to make the first problem go away.
Full variant:
import os
def find_get(path):
files = {}
for file in os.listdir(path):
if os.path.isfile(os.path.join(path,file)):
with open(os.path.join(path,file), "r") as data:
files[file] = data.read()
return files
print(find_get("filex"))
Output:
{'1.txt': 'dsad', '2.txt': 'fsdfs'}
After the you could generate one file from that content, etc.
Key-thing:
os.listdir return a list of files without full path, so you need to concatenate initial path with fount item to operate.
there could be ideally used dicts :)
os.listdir return files and folders, so you need to check if list item is really file
You should check if the file is actually file and not a folder, since you can't open folders for reading. Also, you can't just open a relative path file, since it is under a folder, so you should get the correct path with os.path.join. Check below:
import os
def find_get(folder):
for file in os.listdir(folder):
if not os.path.isfile(file):
continue # skip other directories
f = open(os.path.join(folder, file), 'r')
for line in f:
print line

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