I am trying to open a file with file = filedialog.askopenfile(initialdir='./'), but I need also to know the name of the file opened for other purposes. I know that if the user selects a file, file is not None, otherwise it's something like this:
<_io.TextIOWrapper name='/Users/u/Desktop/e/config.py' mode='r' encoding='US-ASCII'>
but _io.TextIOWrapper objects are not sub-scriptable.
By suggestion, I discovered that there exists another function similar to messagebox.askopenfile, askopenfilename, that instead of opening directly the file, returns just the name of the file. If we want also to open the file, we can open and read it manually:
file_name = filedialog.askopenfilename(initialdir='./')
if file_name != '':
with open(file_name, 'r') as file:
string = ''
for line in file:
string += str(line)
print(string)
Even if this is a good way, I'm still thinking that tkinter should have provided this functionality with messagebox.askopenfile directly.
Navigating trough the Python directory we can find the filedialog.py file, which contains the specifications of both functions, which are very similar:
def askopenfilename(**options):
"Ask for a filename to open"
return Open(**options).show()
askopenfile
def askopenfile(mode = "r", **options):
"Ask for a filename to open, and returned the opened file"
filename = Open(**options).show()
if filename:
return open(filename, mode)
return None
As we can see, the first returns the result of the call to the show function, whereas the second returns an opened file.
Related
I have a folder called "before_manipulation ".
It contains 3 CSV files with names File_A.CSV, File_B.CSV ,File_C.CSV
Current_path : c:/users/before_manipulation [file_A.CSV, File_B.CSV,File_C.CSV]
I have a data manipulation that I need to do in each of the files and after manipulation ,I need to save with the same file names in another directory.
Targeted_path : C:/users/after_manipulation [file_A.CSV, File_B.CSV,File_C.CSV]
I have the logic to do the data manipulation when there is only a single file with Pandas dataframe. When I have multiple files, how to read each file and its name and pass it to my logic ?
Pseudo Code of how I am working if there was one file.
import pandas as pd
df = pd.read_csv('c:/users/before_manipulation/file_A.csv')
... do logic/manipulation
df.to_csv('c:/users/after_manipuplation/file_A.csv')
any help is appreciated.
You can use os.listdir(<path>) to return a list of the files contained within a directory. If you do not pass a variable to <path> it will return the working directory listing.
With the list from os.listdir you can iterate over it, passing the capture filename to the function you already have for data manipulation. Then on the save to you can use the captured filename to save in your desired directory.
In summary the code would look something like this.
import os
import pandas as pd
in_dir = r'c:/users/before_manipulation/'
out_dir = r'c:/users/after_manipulation/'
files_to_run = os.listdir(in_dir)
for file in files_to_run:
print('Running {}'.format(in_dir + file))
df = pd.read_csv(in_dir + file)
...do your logic here to return the changed df you want to save
...
df.to_csv(out_dir + file)
For this to work you would need to have the same shape files for each file you have in the directory, and also you would need to want to do the same logic for each file.
If that is not the case you will need something like a dictionary to save the different manipulations you need to do based on the file name and call those when appropriate.
Assuming you have some logic that works for one file, I'd just put that logic into a function and run it on a for loop.
You'd end up with something like this:
directory = r'c:/users/before_manipulation'
files = ['file_A.CSV', 'File_B.CSV','File_C.CSV']
for file in files:
somefunction(directory + '/' + file)
If you need more info on functions I'd check this out: https://www.w3schools.com/python/python_functions.asp
using pathlib
from pathlib import Path
new_dir = '\\your_path'
files = [file for file in Path(your_dir).glob('*.csv')]
for file in files:
df = pd.read_csv(file)
# .. your logic
df.to_csv(f'{new_dir}\\{file.name}',index=False)
I'm trying to use input to variable to create a file using the input the filename
The only examples I've seen are print(input)
I'm new to Python but trying to write a functional program
thanks
This is nice beginning for you
def create_file():
fn = input('Enter file name: ').strip()
try:
file = open(fn, 'r')
except IOError:
file = open(fn, 'w')
In Python you can use the open() function to create a file (assuming it will be a text file).
The documentation for it is located here
Using your input variable to create the file, you could do it like so:
file = open(input, 'w+')
This will give you a file object which you can write lines to using the write() function.
Is there built error handling for prevent overwriting a file when using numpy.savetxt?
If 'my_file' already exists, and I run
numpy.savetxt("my_file", my_array)
I want an error to be generated telling me the file already exists, or asking if the user is sure they want to write to the file.
You can check if the file already exists before you write your data:
import os
if not os.path.exists('my_file'): numpy.savetxt('my_file', my_array)
You can pass instead of a filename a file handle to np.savetxt(), e.g.,
import numpy as np
a = np.random.rand(10)
with open("/tmp/tst.txt", 'w') as f:
np.savetxt(f,a)
So you could write a helper for opening the file.
Not in Numpy. I suggest writing to a namedTemporaryFile and checking if the destination file exists. If not, rename the file to a concrete file on the system. Else, raise an error.
Not an error handler, but it's possible to create a new version in the form of:
file
filev2
filev2v3
filev2v3v4
so that no file ever gets overwritten.
n=2
while os.path.exists(f'{file}.txt'):
file = file + f'v{n}'
n+=1
I do not understand how this method works. Here is the code
BOOL isDir = NULL;
BOOL returnVal;
path = #"/Users/me/Desktop/kkk";
returnVal = [[NSFileManager defaultManager] fileExistsAtPath:path isDirectory:&isDir];
And here are the results if:
1) kkk is a file
returnVal = NO
isDir = NO
2) kkk is an empty directory
returnVal = YES
isDir = YES
Scenario #2 seems to work as expected, but according to the documentation:
path
The path of a file or directory. If path begins with a tilde (~), it must first be expanded with stringByExpandingTildeInPath, or this method will return NO.
isDirectory
Upon return, contains YES if path is a directory or if the final path element is a symbolic link that points to a directory, otherwise contains NO. If path doesn’t exist, this value is undefined upon return. Pass NULL if you do not need this information.
So for scenario #1 shouldnt the result be the following?
returnVal = YES
isDir = NO
1) Edit
For the comments below.
But the files do exist. I create the file manually to test it. lol. its only a program with 4 lines of code. I have both file/folder on the desktop. First i put a file there called "kkk" (with no extention) then i remove the file and place a folder there called "kkk". It works for the folder, but not for the file. Interestingly, if the file has an extension, it works. So is there something wrong with a file with no extension ? (are you guys still not able to reproduce it with no extention?)
2) EDIT
Thanks for helping me solve this guys. I have my Mac set to display the extension of files. But it seems Mac as an odd behavior. I select the file "kk.plist" and then rename the file to "kk" as you see in the image. As soon as i do this Mac OSx automatically selects the hide extension option. So when i thought the file was "kk", it was still "kk.plist" with its extension hidden. As you can see, both files have the same extension, one is hidden, the other is not. I didnt realize hidden extensions can be applied to one file only. Thanks.
1) kkk is a file
returnVal = NO
isDir = NO
⋮
So for scenario #1 shouldnt the result be the following?
returnVal = YES
isDir = NO
Yes. But be wary of the Finder hiding things from you when you're trying to verify results from this method.
As you found, one example is hiding extensions: you gave a path with no extension and were surprised when it didn't find a file that you thought had no extension; in truth, it still had an extension, which the Finder had hidden, so it still did not match the path, so the result you got was correct.
The other example is hidden (a.k.a. invisible) items. You may get a result of YES for a file that you can't find in the Finder. The Go command will temporarily reveal an invisible directory, but won't help you for files.
Whenever fileExists:isDirectory:'s results surprise you, and the Finder appears to show that the results are wrong, try to ls the path in the Terminal:
ls -dl /path/to/item
If that command prints a description of the item, then it exists. If it prints an error, then it doesn't. You can also tell from the output whether the item is a directory or not.
I ran into this problem when uploading a file with a super long name - my database field was only set to 50 characters. Since then, I have increased my database field length, but I'd like to have a way to check the length of the filename before uploading. Below is my code. The validation returns '85' as the character length. And it returns the same count for every different file I upload (none of which have a file name length of 85).
<cfscript>
missing_info = "<p>There was a slight problem with your submission. The following are required or invalid:</p><ul>";
// Check the length of the file name for our database field
if ( len(Form["ResumeFile1"]) gt 100 )
{
missing_info = missing_info & "<li>'Resume File 1' is invalid. Character length must be less than 100. Current count is " & len(Form["ResumeFile1"]) & ".</li>";
validation_error = true;
ResumeFileInvalidMarker = true;
}
</cfscript>
Anyone see anything wrong with this?
Thanks!
http://www.cfquickdocs.com/cf9/#cffile.upload
After you upload the file, the variable "clientFileName" will give you the name of the uploaded file, without a file extension.
The only way to read the filename before you upload it would be to use JavaScript to read and parse the value (file path) in the file field.
A quick clarification in the wording of your question. By the time your code executes the file upload has already happened. The file resides in a temporary directory on the ColdFusion server and the form field related to the file upload contains the temporary filename for that file. Aside from checking to see if a file has been specified, do not do anything directly with that file or you'll be circumventing some built in security.
You want to use the cffile tag with the upload action (or equivalent udf) to move the temp file into a folder of your choosing. At that point you get access to a structure containing lots of information. Usually I "upload" into a temporary directory for the application, which should be outside of the webroot for security.
At this point you'll then want to do any validation against the file, such as filename length, file type, file size, etc and delete the file if it fails any checks. If it passes all checks then you move it into it's final destination which may be inside the webroot.
In your case you'll want to check the cffile structure element clientFile which is the original filename including extension (which you'll need to check, since an extension doesn't need to be present and can be any length).