Issue finding a file in a list to be rewritten - python

Very new to Python and programming in general so apologies if I am missing anything straightforward.
I am trying to iterate through a directory and open the included .txt files and modify them with new content.
import os
def rootdir(x):
for paths, dirs, files in os.walk(x):
for filename in files:
f=open(filename, 'r')
lines=f.read()
f.close()
for line in lines:
f=open(filename, 'w')
newline='rewritten content here'
f.write(newline)
f.close()
return x
rootdir("/Users/russellculver/documents/testfolder")`
Is giving me: IOError: [Errno 2] No such file or directory: 'TestText1.rtf'
EDIT: I should clarify there IS a file named 'TestText1.rtf' in the folder specified in the function argument. It is the first one of three text files.
When I try moving where the file is closed / opened as seen below:
import os
def rootdir(x):
for paths, dirs, files in os.walk(x):
for filename in files:
f=open(filename, 'r+')
lines=f.read()
for line in lines:
newline='rewritten content here'
f.write(newline)
f.close()
return x
rootdir("/Users/russellculver/documents/testfolder")
It gives me: ValueError: I/O operation on closed file
Thanks for any thoughts in advance.
#mescalinum Okay so I've made amendments to what I've got based on everyones assistance (thanks!), but it is still failing to enter the text "newline" in any of the .txt files in the specified folder.
import os
x = raw_input("Enter the directory here: ")
def rootdir(x):
for dirpaths, dirnames, files in os.walk(x):
for filename in files:
try:
with open(os.dirpaths.join(filename, 'w')) as f:
f.write("newline")
return x
except:
print "There are no files in the directory or the files cannot be opened!"
return x

From https://docs.python.org/2/library/os.html#os.walk:
os.walk(top, topdown=True, onerror=None, followlinks=False)
Generate the file names in a directory tree by walking the tree either top-down or bottom-up. For each directory in the tree rooted at directory top (including top itself), it yields a 3-tuple (dirpath, dirnames, filenames).
dirpath is a string, the path to the directory. dirnames is a list of the names of the subdirectories in dirpath (excluding '.' and '..'). filenames is a list of the names of the non-directory files in dirpath. Note that the names in the lists contain no path components. To get a full path (which begins with top) to a file or directory in dirpath, do os.path.join(dirpath, name).
Also, f.close() should be outside for line in lines, otherwise you call it multiple times, and the second time you call it, f is already closed, and it will give that I/O error.
You should avoid explicitly open()ing and close()ing files, like:
f=open(filename, 'w')
f.write(newline)
f.close()
and instead use context managers (i.e. the with statement):
with open(filename, 'w'):
f.write(newline)
which does exactly the same thing, but implicitly closes the file when the body of with is finished.

Here is the code that does as you asked:
import os
def rootdir(x):
for paths, dirs, files in os.walk(x):
for filename in files:
try:
f=open(os.path.join(dirpath, name), 'w')
f.write('new content here')
f.close()
except Exception, e:
print "Could not open " + filename
rootdir("/Users/xrisk/Desktop")
However, I have a feeling you don’t quite understand what’s happening here (no offence). First have a look at the documentation of os.walk provided by #mescalinum . The third tuple element files will contain only the file name. You need to combine it with paths to get a full path to the file.
Also, you don’t need to read the file first to write to it. On the other hand, if you want to append to the file, you should use the mode 'a' when opening the file
In general, when reading/writing a file, you only close it after finishing all the read/writes. Otherwise you will get an exception.
Thanks #mescalinum

Related

Incorrect filename when iterating through files

I want to add a character at the end of each line in all the files in a folder, so I've written some code in order to iterate through each file and add the desired change, however the output files have different filenames than the originals, below is the code that I've put together
import os
output = '/home/test/Playground/Python/filemodification/output/'
def modification():
with open(files, 'r') as istr:
with open(str(output) + str(files), 'w') as ostr:
for line in istr:
line = line.rstrip('\n') + 'S'
print(line, file=ostr)
directory = '/home/test/Playground/Python/filemodification/input'
for files in os.scandir(directory):
#print(files.path)
print(files)
#print(output)
#print(type(files))
modification()
Once I run the code I get the following filename
<DirEntry 'input.txt'>
and this is the original filename
input.txt
I know the issue is probably related with this
with open(str(output) + str(files), 'w') as ostr:
but I haven't found a way to perform this task differently
If someone could point me in the right direction or provide a code example that can acommplish this task it would be greatly appreciated
Thanks
os.scandir returns os.DirEntry objects. You can get their filename by accessing their .name attribute, or their full path through .path.
E.g.:
for entry in os.scandir(directory):
print(entry.path)

FileNotFoundError: [Errno 2] No such file or directory despite the file definitely existing [duplicate]

This question already has answers here:
open() gives FileNotFoundError / IOError: '[Errno 2] No such file or directory'
(8 answers)
Closed 6 months ago.
I've been working on this bit of code trying to open multiple files in a directory. The directory contains 10 text files. I want to open each of the files, do some stuff to it (namely remove stop words) and output the transformed text into a new file in a different directory. However, I have this problem:
FileNotFoundError: [Errno 2] No such file or directory: '1980'
The file definitely exists in the directory and I have been giving the absolute path. I have looked at the current working directory before opening the file and it does not return the absolute path I gave it, rather the directory where this project is located. Any help in getting the code to open the necessary files and write the result to the output file would be greatly appreciated! Here is my code:
path = 'C:/Users/User/Desktop/mini_mouse'
output = 'C:/Users/User/Desktop/filter_mini_mouse/mouse'
for root, dir, files in os.walk(path):
for file in files:
print(os.getcwd())
with open(file, 'r') as f, open('NLTK-stop-word-list', 'r') as f2:
x = ''
mouse_file = f.read().split() # reads file and splits it into a list
stopwords = f2.read().split()
x = (' '.join(i for i in mouse_file if i.lower() not in (x.lower() for x in stopwords)))
with open('out', 'w') as output_file:
output_file.write((' '.join(i for i in mouse_file if i.lower() not in (x.lower() for x in stopwords))))
Are you on Windows? Whenever I do absolute paths on Windows I need to use backslash() for pathing instead of forward slash (/).
The problem with your code is the fact '1980' is not the full path to the file it is just a string. You should append the rest of the path like below, using for example the path.join:
with open(os.path.join(path, file), 'r') as f, open(os.path.join(path, 'NLTK-stop-word-list'), 'r') as f2:
Then Python will be able to find the file and open it in read mode.

Python - IOError: [Errno 13] Permission denied

Im trying to get a local directory from argv and iterate through the folder and print the contents of each file within. However i am getting a [Errno] 13 saying permission denied. Ive tried researching the problem but have come up empty handed.
#!/usr/bin/python
import os
import sys
path = open(sys.argv[1],'r') #'inputs/' path to working input dir
file_list = os.listdir(path) #create list of filenames in path dir
for fn in file_list:
file = open(path+'/'+fn) #open each file in dir for manipulation
for line in file:
print(line)
os.listdir(), as its name implies, returns a list of all occupants of the given directory, including both files and directories (and, if you're on Unix/Linux, other stuff like symlinks and devices and whatnot). You are then blindly trying to open() each item in the list and print() its contents. Unfortunately, open() only works on file-like objects, and specifically does not work on directories, hence Errno 13, Permission Denied.
An alternative is to use os.scandir(), which works a little bit differently. Instead of returning a flat list that you can read immediately, os.scandir() returns a generator which essentially gives you objects as you ask for them, instead of giving them all to you at once. In fact, the following code adapted from the docs is a good starting place for what you need:
for entry in os.scandir(path):
if entry.is_file():
print(entry.name)
os.scandir() is returning DirEntry objects. Simply use os.path.join() to create a full pathname out of the path argument you pass to os.listdir() in your original code, and entry.name from the code above, and then, using the with context manager, open() the file and display its contents:
for entry in os.scandir(path):
if entry.is_file():
with open(os.path.join(path, entry), "r") as f:
for line in f:
print(line)
One of the advantages of using with is that you don't have to remember to close the file handle that is assigned when you use something like this:
f = open("myfile.txt, "r")
# do stuff with f
...
f.close()
Otherwise, you have a dangling file handle that could potentially cause problems, depending on how many there are and what you've done with them. It's just a good practice to close() what you open(). With with, you don't have to worry about it - the file handle is closed as soon as you exit the block.

Python for loop only executes once

I am currently working on some code that will look through multiple directories from an .ini file then print and copy them to a new directory. I ran into a problem where the for loop that prints the files only executes once when it is supposed to execute 5 times. How can i fix it so the for loop works every time it is called?
Code:
def copyFiles(path):
rootPath = path
print(rootPath)
pattern = "*.wav"
search = ""
#searches the directories for the specified file type then prints the name
for root, dirs, files in os.walk(rootPath):
for filename in fnmatch.filter(files, pattern):
print(filename)
def main():
#opens the file containing all the directories
in_file = open('wheretolook.ini', "r")
#create the new directory all the files will be moved to
createDirectory()
#takes the path names one at a time and then passes them to copyFiles
for pathName in in_file:
copyFiles(pathName)
Output i get from running my code
The output should have the 0 through 4 files under every diretory.
Thank you for the help!
The pathName you get when iterating over the file has a newline character at the end for each line but the last. This is why you get the blank lines in your output after each path is printed.
You need to call strip on your paths to remove the newlines:
for pathName in in_file:
copyFiles(pathname.strip())
You could be more restrictive and use rstrip('\n'), but I suspect getting rid of all leading and trailing whitespace is better anyway.

How to search string in files recursively in python

I am trying to find all log files in my C:\ and then in these log file find a string. If the string is found the output should be the abs path of the log file where the string is found. below is what I have done till now.
import os
rootdir=('C:\\')
for folder,dirs,file in os.walk(rootdir):
for files in file:
if files.endswith('.log'):
fullpath=open(os.path.join(folder,files),'r')
for line in fullpath.read():
if "saurabh" in line:
print(os.path.join(folder,files))
Your code is broken at:
for line in fullpath.read():
The statement fullpath.read() will return the entire file as one string, and when you iterate over it, you will be iterating a character at a time. You will never find the string 'saurabh' in a single character.
A file is its own iterator for lines, so just replace this statement with:
for line in fullpath:
Also, for cleanliness, you might want to close the file when you're done, either explicitly or by using a with statement.
Finally, you may want to break when you find a file, rather than printing the same file out multiple times (if there are multiple occurrences of your string):
import os
rootdir=('C:\\')
for folder, dirs, files in os.walk(rootdir):
for file in files:
if file.endswith('.log'):
fullpath = os.path.join(folder, file)
with open(fullpath, 'r') as f:
for line in f:
if "saurabh" in line:
print(fullpath)
break

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