I am trying to find the file with the largest number in the filename in each subdirectory. This is so I can acomplish opening the most recent file in each subdirectory. Each file will follow the naming convetion of date filename.xlsx.

Ex. 20180620 file name.xlsx

I have a code that works for searching one directory for largest numbers.

dirname = py.path.local(path)list_of_files = []for file in dirname.visit(fil='*.xlsx', bf=True):list_of_files.append(file)largest = max(list_of_files)
print (largest)

I am pretty new to Python and I can't quite figure out how to make this style of code work looking for the file with the largest number in each subdirectory within a directory. I have tried many variations off of this following code, but I can't get it to print out just the file with the largest number from each subdirectory.

list_of_files = []for root, dirs, files in os.walk(path):for name in files:if name.endswith((".xlsx")):list_of_files.append(files)largest = max(list_of_files)print (largest)

Any help would be greatly appreciated!

Your second code block does almost what you want to do, you've just nested your operations incorrectly.

for root, dirs, files in os.walk(path):# new subdir, so let's make a new...list_of_files = []for name in files:if name.endswith((".xlsx")):list_of_files.append(name)  # you originally appended the list of all names!# once we're here, list_of_files has all the filenames in it,# so we can find the largest and print itlargest = max(list_of_files)print (largest)

If I can suggest a shorter solution:

[(root, max(fname for fname in files if fname.endswith(".xlsx"))) forroot, dirs, files in os.walk(path)]

This will give you a list of (dirname, largest_filename) pairs, rather than just printing them to the screen.