I have been looking for days and was wondering if there is any way to read all the files in a directory in python without using a loop. The reason I ask is because when I go to write the files it goes through the loop again and overwrites all my information or doubles it when I only need to grab one file.
I love pathlib for such tasks
from pathlib import Path
# create a posix path object
folder_path = Path('/path/to/your/folder')
# iterate over directory and store filenames in a list
files_list = list(folder_path.iterdir())
# access file names
print(files_list[0].name)
always pretty handy
Related
I am trying to save all entries of os.listdir("./oldcsv") separately in a list but I don't know how to manipulate the output before it is processed.
What I am trying to do is generate a list containing the absolute pathnames of all *.csv files in a folder, which can later be used to easily manipulate those files' contents. I don't want to put lots of hardcoded pathnames in the script, as it is annoying and hard to read.
import os
for file in os.listdir("./oldcsv"):
if file.endswith(".csv"):
print(os.path.join("/oldcsv", file))
Normally I would use a loop with .append but in this case I cannot do so, since os.listdir just seems to create a "blob" of content. Probably there is an easy solution out there, but my brain won't think of it.
There's a glob module in the standard library that can solve your problem with a single function call:
import glob
csv_files = glob.glob("./*.csv") # get all .csv files from the working dir
assert isinstance(csv_files, list)
Cheers everybody,
I need help with something in python 3.6 exactly. So i have structure of data like this:
|main directory
| |subdirectory's(plural)
| | |.wav files
I'm currently working from a directory where main directory is placed so I don't need to specify paths before that. So firstly I wanna iterate over my main directory and find all subdirectorys. Then in each of them I wanna find the .wav files, and when done with processing them I wanna go to next subdirectory and so on until all of them are opened, and all .wav files are processed. Exactly what I wanna do with those .wav files is input them in my program, process them so i can convert them to numpy arrays, and then I convert that numpy array into some other object (working with tensorflow to be exact, and wanna convert to TF object). I wrote about the whole process if anybody has any fast advices on doing that too so why not.
I tried doing it with for loops like:
for subdirectorys in open(data_path, "r"):
for files in subdirectorys:
#doing some processing stuff with the file
The problem is that it always raises error 13, Permission denied showing on that data_path I gave him but when I go to properties there it seems okay and all permissions are fine.
I tried some other ways like with os.open or i replaced for loop with:
with open(data_path, "r") as data:
and it always raises permission denied error.
os.walk works in some way but it's not what I need, and when i tried to modify it id didn't give errors but it also didnt do anything.
Just to say I'm not any pro programmer in python so I may be missing an obvious thing but ehh, I'm here to ask and learn. I also saw a lot of similiar questions but they mainly focus on .txt files and not specificaly in my case so I need to ask it here.
Anyway thanks for help in advance.
Edit: If you want an example for glob (more sane), here it is:
from pathlib import Path
# The pattern "**" means all subdirectories recursively,
# with "*.wav" meaning all files with any name ending in ".wav".
for file in Path(data_path).glob("**/*.wav"):
if not file.is_file(): # Skip directories
continue
with open(file, "w") as f:
# do stuff
For more info see Path.glob() on the documentation. Glob patterns are a useful thing to know.
Previous answer:
Try using either glob or os.walk(). Here is an example for os.walk().
from os import walk, path
# Recursively walk the directory data_path
for root, _, files in walk(data_path):
# files is a list of files in the current root, so iterate them
for file in files:
# Skip the file if it is not *.wav
if not file.endswith(".wav"):
continue
# os.path.join() will create the path for the file
file = path.join(root, files)
# Do what you need with the file
# You can also use block context to open the files like this
with open(file, "w") as f: # "w" means permission to write. If reading, use "r"
# Do stuff
Note that you may be confused about what open() does. It opens a file for reading, writing, and appending. Directories are not files, and therefore cannot be opened.
I suggest that you Google for documentation and do more reading about the functions used. The documentation will help more than I can.
Another good answer explaining in more detail can be seen here.
import glob
import os
main = '/main_wavs'
wavs = [w for w in glob.glob(os.path.join(main, '*/*.wav')) if os.path.isfile(w)]
In terms of permissions on a path A/B/C... A, B and C must all be accessible. For files that means read permission. For directories, it means read and execute permissions (listing contents).
I have a script that creates a list of local files by path name that I would like to see deleted. The essence of my problem in the code below.
If it's easier just to move these files rather than delete them, that's an option. I've seen it might be an option to set the directory before I can get it do delete but I'm hoping for a more efficient function that will just read the paths and deal with them.
I don't need any function to discriminate between any file path names stored in the list. I want each file stored in the list, OUT.
The code as is now gives the error:
TypeError: remove: illegal type for path parameter
Code:
import os
files = ['/users/computer/site/delete/photo1.jpg', '/users/computer/site/delete/photo3.jpg']
os.remove(files)
os.remove() takes a single path as argument, not a list of paths. You have to do something like:
for f in files:
os.remove(f)
You could use a list comprehension
[os.remove(f) for f in ['/users/computer/site/delete/photo1.jpg', '/users/computer/site/delete/photo3.jpg']]
For starters, you are calling os.remove(LIST CALLED files).
You want to iterate through the files and call os.remove on each individual file.
for file in files:
os.remove(file)
You can't delete the list at once. You must iterate over all of the files and delete each one.
The code for removing files from the list -
import os
files = ['/users/computer/site/delete/photo1.jpg', '/users/computer/site/delete/photo3.jpg']
for f in files:
os.remove(f)
I am using Python 3.5 to analyze data contained in csv files. These files are contained in a "figs" directory, which is contained in a case directory, which is contained in an overall data directory, e.g.:
/strm1/serino/DATA/06052009/figs
Or more generally:
/strm1/serino/DATA/case_date_in_MMDDYYYY/figs
The directory I am starting in is '/strm1/serino/DATA/,' and each subdirectory is the month, day, and year of a case I am working with. Each subdirectory contains another subdirectory named 'figs,' and that is the location of each case's csv file. To be exact:
/strm1/serino/DATA/case_date_in_MMDDYYYY/figs/case_date_in_MMDDYYYY.csv
So, I would like to start in my DATA directory and go through its subdirectories to find those that have the MMDDYYYY naming. However, some of the case directories may be named with a state abbreviation at the end, like: '06052009_TX.' Therefore, instead of matching the MMDDYYYY naming exactly, it could be something as simple as verifying that the directory name contains any number 1 through 9.
Once I am in the first subdirectory (the case directory) I would like to move into the 'figs' subdirectory. Once there, I want to access the csv file with the same naming convention as the first subdirectory (the case directory). I will fill existing arrays with the data contained in each csv file.
Basically, my question concerns navigating through multiple subdirectories that match a certain naming convention and ultimately accessing the data file at the "end." I was naively playing around with glob, fnmatch, os.listdir, and os.walk, but I could not get anything close enough to working that I feel would be helpful to include. I am not very familiar with those modules. What I can include is what I am going for:
for dirs in data_dir that contain a number:
go into this directory
go into 'figs' directory
read data from the csv file whose name matches its case directory name (or whose name format matches the case directory name format)
I have come across related questions, but I have not been able to apply their answers in the way that I would like, especially with nested directories. I really appreciate the help, and let me know if I need to clarify anything.
The following should get you going. It uses the datetime.strptime() function to attempt to convert each folder name into a valid datetime object. If the conversion fails, then you know that the folder name is not in the correct format and can be skipped. It then attempts to parse any CSV file found in the corresponding fig folder:
from datetime import datetime
import glob
import csv
import os
dirpath, dirnames, filenames = next(os.walk('/strm1/serino/DATA'))
for dirname in dirnames:
if len(dirname) >= 8:
try:
dt = datetime.strptime(dirname[:8], '%m%d%Y')
print(dt, dirname)
csv_folder = os.path.join(dirpath, dirname)
for csv_file in glob.glob(os.path.join(csv_folder, 'figs', '*.csv')):
with open(csv_file, newline='') as f_input:
csv_input = csv.reader(f_input)
for row in csv_input:
print(row)
except ValueError as e:
pass
You listed several problems above. Which one are you stuck on? It seems like you already know how to navigate the file storage system using os.path. You may not know of the function os.path.join() which allows you to manually specify a file path relative to a file as such:
os.path.abspath(os.path.join(os.path.dirname(__file__), '../..', 'Data/TrailShelters/'))
To break down the above:
os.path.dirname(__file__) returns the path of the current file. '../..' means: go up two levels in the folder hierarchy. And Data/TrailShelters/ is the directory I wish to navigate to.
How does this apply to your particular case? Well, you will need to make some adaptations but you can store the os.path of the parent directory in a variable. Then you can essentially use a while sub_dir is not null loop to iterate through subdirectories. For every subdirectory you will want to examine its os.path and extract the particular part of the path you are interested in. Then you can simply use something like: if 'TN' in subdirectory_name to determine if it is a subdirectory you are interested in. If so; then update the saved os.path of the parent directory by appending the path to the subdirectory. Does that make any sense?
If I am to read a number of files in Python 3.2, say 30-40, and i want to keep the file references in a list
(all the files are in a common folder)
Is there anyway how i can open all the files to their respective file handles in the list, without having to individually open every file via the file.open() function
This is simple, just use a list comprehension based on your list of file paths. Or if you only need to access them one at a time, use a generator expression to avoid keeping all forty files open at once.
list_of_filenames = ['/foo/bar', '/baz', '/tmp/foo']
open_files = [open(f) for f in list_of_filenames]
If you want handles on all the files in a certain directory, use the os.listdir function:
import os
open_files = [open(f) for f in os.listdir(some_path)]
I've assumed a simple, flat directory here, but note that os.listdir returns a list of paths to all file objects in the given directory, whether they are "real" files or directories. So if you have directories within the directory you're opening, you'll want to filter the results using os.path.isfile:
import os
open_files = [open(f) for f in os.listdir(some_path) if os.path.isfile(f)]
Also, os.listdir only returns the bare filename, rather than the whole path, so if the current working directory is not some_path, you'll want to make absolute paths using os.path.join.
import os
open_files = [open(os.path.join(some_path, f)) for f in os.listdir(some_path)
if os.path.isfile(f)]
With a generator expression:
import os
all_files = (open(f) for f in os.listdir(some_path)) # note () instead of []
for f in all_files:
pass # do something with the open file here.
In all cases, make sure you close the files when you're done with them. If you can upgrade to Python 3.3 or higher, I recommend you use an ExitStack for one more level of convenience .
The os library (and listdir in particular) should provide you with the basic tools you need:
import os
print("\n".join(os.listdir())) # returns all of the files (& directories) in the current directory
Obviously you'll want to call open with them, but this gives you the files in an iterable form (which I think is the crux of the issue you're facing). At this point you can just do a for loop and open them all (or some of them).
quick caveat: Jon Clements pointed out in the comments of Henry Keiter's answer that you should watch out for directories, which will show up in os.listdir along with files.
Additionally, this is a good time to write in some filtering statements to make sure you only try to open the right kinds of files. You might be thinking you'll only ever have .txt files in a directory now, but someday your operating system (or users) will have a clever idea to put something else in there, and that could throw a wrench in your code.
Fortunately, a quick filter can do that, and you can do it a couple of ways (I'm just going to show a regex filter):
import os,re
scripts=re.compile(".*\.py$")
files=[open(x,'r') for x in os.listdir() if os.path.isfile(x) and scripts.match(x)]
files=map(lambda x:x.read(),files)
print("\n".join(files))
Note that I'm not checking things like whether I have permission to access the file, so if I have the ability to see the file in the directory but not permission to read it then I'll hit an exception.