On Thursday, September 24, 2020 at 4:37:07 PM UTC+2, Terry Reedy wrote:
> On 9/23/2020 7:24 PM, pascal z via Python-list wrote:
> > Please advise if the following is ok (i don't think it is)
> >
> > #!/usr/bin/env python3
> > # -*- coding: utf-8 -*-
> >
> > import os
> >
> > csv_contents = ""
> > output_file = '/home/user/Documents/csv/output3csv.csv'
> > Lpath = '/home/user/Documents/'
> >
> > csv_contents = "FOLDER PATH;Size in Byte;Size in Kb;Size in Mb;Size in Gb\n"
> >
> > d_size = 0
> > for root, dirs, files in os.walk(Lpath, topdown=False):
> > for i in files:
> > d_size += os.path.getsize(root + os.sep + i)
> > csv_contents += "%s ;%.2f ;%.2f ;%.2f ;%.2f \n" % (root,
> > d_size, d_size/1024, d_size/1048576, d_size/1073741824)
> >
> > counter = Lpath.count(os.path.sep)
> > if counter < 5:
> > for f in os.listdir(Lpath):
> > path = os.path.join(Lpath, f)
> > f_size = 0
> > f_size = os.path.getsize(path)
> > csv_contents += "%s ;%.2f ;%.2f ;%.2f ;%.2f \n" %
> > (path, f_size, f_size/1024, f_size/1048576, f_size/1073741824)
> >
> > fp = open(output_file, "w")
> > fp.write(csv_contents)
> > fp.close()
>
>
> Read
> https://docs.python.org/3/faq/programming.html#what-is-the-most-efficient-way-to-concatenate-many-strings-together
> --
> Terry Jan Reedy
Thanks for this tip. I do think it's better to use lists than concatenate into
string variable. However, writing a list to a csv file is not something easy.
If strings stored into the list have commas and single quotes (like song
title's), it messes up the whole csv when it first meets this. Example with arr
as list:
import csv
import io
(...)
csv_contents = "%s;%s;%s;%.2f;%.2f;%.2f;%.2f;%s" % (vfolder_path, vfile_name,
vfolder_path_full, 0.00, 0.00, 0.00,0.00, "folder")
arr.append([csv_contents])
b = io.BytesIO()
with open(CSV_FILE,'w', newline ='\n') as f:
#write = csv.writer(f,delimiter=';')
#write = csv.writer(f,quotechar='\'',
quoting=csv.QUOTE_NONNUMERIC,delimiter=',')
write = csv.writer(f,b)
for row in arr:
write.writerows(row)
(...)
string samples: ;'Forgotten Dreams' Mix.mp3;'Awakening of a Dream' Ambient
Mix.mp3;Best of Trip-Hop & Downtempo & Hip-Hop Instrumental.mp3;2-Hour _ Space
Trance.mp3
for the titles above, the easiest thing to write csv for me is
(...)
csv_contents += "%s;%s;%s;%.2f;%.2f;%.2f;%.2f;%s" % (vfolder_path, vfile_name,
vfolder_path_full, 0.00, 0.00, 0.00,0.00, "folder"
with open(CSV_FILE,'w') as f:
f.write(csv_contents)
csv_contents can be very large and it seems to work. It can concatenate 30k
items and it's ok. Also with the above, I have the expected result into each of
the 8 rows having the corresponding data. This is not always the case with csv
writerows. If it meets a character it can't process, from there everything go
into a single cell row. The split on semi colon from doesnt work anymore.
I am not allowed to change the name of the files (it could be used later
somewhere else, making side effects...).
--
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