Quote:perhaps I can get to documenting the entire code.
I wrote it in 10 minutes, and haden't planned on documenting, I have my regular work to do, as well as answering so many questions (as a volunteer) on the forum.
Always glad to answer specific questions.
Quote:What does this part of the code below? Could you provide some explanation behind the lines of code as comments?
def read_csv_file(filename):
parts = list(filename.parts)
# parts = ['/', 'media', '/', 'stubens', '/', 'DataDrive-3XT','/', 'projs', '/', 'T-Z', '/', 'T', '/', 'TryStuff', '/', 'data', '/', 'csv', '/', 'IllinoisData.csv']
parts[-1] = f"{filename.stem}Modified{filename.suffix}"
# parts[-1] = 'IllinoisDataModified.csv'
# parts = ['/', 'media', '/', 'stubens', '/', 'DataDrive-3XT','/', 'projs', '/', 'T-Z', '/', 'T', '/', 'TryStuff', '/', 'data', '/', 'csv', '/', 'IllinoisDataModified.csv']
parts[0] = ''
# removes '/' from index 0 because join will add it back again
# parts = ['media', '/', 'stubens', '/', 'DataDrive-3XT','/', 'projs', '/', 'T-Z', '/', 'T', '/', 'TryStuff', '/', 'data', '/', 'csv', '/', 'IllinoisDataModified.csv']
outfilename = Path(f"{'/'.join(parts)}")
# join fileparts back together
# outfilename = '/media/stubens/DataDrive-3XT/projs/T-Z/T/TryStuff/data/csv/IllinoisDataModified.csv'
print(f"new output file name: {outfilename}")
# will print
# '/media/stubens/DataDrive-3XT/projs/T-Z/T/TryStuff/data/csv/IllinoisDataModified.csv'
# open two files, filename as input (fp), outfilename as output (fout)
with filename.open() as fp, outfilename.open('w') as fout:
# set csv reader to flename (fp)
crdr = csv.reader(fp, delimiter=',')
# set csv writer to outfilename (fout), delimiter = ','
cwrtr = csv.writer(fout, delimiter=',')
# for each row in crdr (csv input)
for row in crdr:
# print the row
print(row)
# ...
# Your code goes here
# ...
# write modified row
cwrtr.writerow(row)(Dec-07-2020, 10:17 PM)Larz60+ Wrote: [ -> ]Quote:What does this part of the code below? Could you provide some explanation behind the lines of code as comments?
for example, filename = Path('/media/stubens/DataDrive-3XT/projs/T-Z/T/TryStuff/data/csv/IllinoisData.csv')
def read_csv_file(filename): parts = list(filename.parts) # parts = ['/', 'media', '/', 'stubens', '/', 'DataDrive-3XT','/', 'projs', '/', 'T-Z', '/', 'T', '/', 'TryStuff', '/', 'data', '/', 'csv', '/', 'IllinoisData.csv'] parts[-1] = f"{filename.stem}Modified{filename.suffix}" # parts[-1] = 'IllinoisDataModified.csv' # parts = ['/', 'media', '/', 'stubens', '/', 'DataDrive-3XT','/', 'projs', '/', 'T-Z', '/', 'T', '/', 'TryStuff', '/', 'data', '/', 'csv', '/', 'IllinoisDataModified.csv'] parts[0] = '' # removes '/' from index 0 because join will add it back again # parts = ['media', '/', 'stubens', '/', 'DataDrive-3XT','/', 'projs', '/', 'T-Z', '/', 'T', '/', 'TryStuff', '/', 'data', '/', 'csv', '/', 'IllinoisDataModified.csv'] outfilename = Path(f"{'/'.join(parts)}") # join fileparts back together # outfilename = '/media/stubens/DataDrive-3XT/projs/T-Z/T/TryStuff/data/csv/IllinoisDataModified.csv' print(f"new output file name: {outfilename}") # will print # '/media/stubens/DataDrive-3XT/projs/T-Z/T/TryStuff/data/csv/IllinoisDataModified.csv' # open two files, filename as input (fp), outfilename as output (fout) with filename.open() as fp, outfilename.open('w') as fout: # set csv reader to flename (fp) crdr = csv.reader(fp, delimiter=',') # set csv writer to outfilename (fout), delimiter = ',' cwrtr = csv.writer(fout, delimiter=',') # for each row in crdr (csv input) for row in crdr: # print the row print(row) # ... # Your code goes here # ... # write modified row cwrtr.writerow(row)
from tkinter.filedialog import askopenfilename
from pathlib import Path
import sys
import csv
def get_filename():
filename = Path(askopenfilename(filetypes=[("CSV files","*.csv")]))
return filename
def read_csv_file(filename):
parts = list(filename.parts)
if __name__ == '__main__': #This executes the code!
read_csv_file(get_filename())If I run the above code, I have the Unused variable 'parts'pylint(unused-variable) message. I do understand the parts variable is not defined, but how can it run anyway in the code Larz60 provided me? I can't find the variable parts defined in the code anyway...Python_User Wrote:I can't find the variable parts defined in the code anyway...parts is an attribute pathlib that Larz60+ use here.filename from tkinter.filedialog import askopenfilename
from pathlib import Path
import csv
def get_filename():
filename = Path(askopenfilename(filetypes=[("CSV files", "*.csv")]))
return filename
def read_csv_file(filename):
# parts = list(filename.parts)
with open(filename) as fp:
crdr = csv.reader(fp, delimiter=',')
for row in crdr:
print(row)
if __name__ == '__main__':
read_csv_file(get_filename())Output:['name', 'origin', 'dest']
['xxx', 'uk', 'france']
['yyyy', 'norway', 'finland']
['zzzz', 'denmark', 'canada']import csv
from pathlib import Path
from tkinter.filedialog import askopenfilename
import sys
def read_csv_file(filename):
parts = list(filename.parts)
parts[-1] = f"{filename.stem}Modified{filename.suffix}"
parts[0] = ''
outfilename = Path(f"{'/'.join(parts)}")
print(f"new output file name: {outfilename}")
with filename.open() as fp, outfilename.open('w') as fout:
crdr = csv.reader(fp, delimiter=',')
cwrtr = csv.writer(fout, delimiter=',')
for row in crdr:
print(row)
# Modify row as desired here
cwrtr.writerow(row)
def get_filename():
badcount = 0
while(True):
try:
if badcount > 2:
print("Three strikes and your out!")
sys.exit(-1)
filename = Path(askopenfilename(filetypes=[("CSV files","*.csv")]))
break
except TypeError:
badcount += 1
print(f"bad filename, try again")
return filename
if __name__ == '__main__':
read_csv_file(get_filename())Please note f-strings are not being properly displayed. items within brackets should be highlighted as they are placeholders for the variable they contain.