How to find size of a csv and either be able to iterate on the reader object

Asked Jun 12 '19 at 10:14

Active Jun 12 '19 at 10:27

Viewed 36 times

I want to have the number of rows for some CSV files.

I have found that can be easily done with len&list functions.

reader = csv.reader(base_data, delimiter=',', quoting=csv.QUOTE_MINIMAL, lineterminator="\n"
total_line = len(list(reader))

The problem is that after have the information about the number of row of the csv file, I would like to iterate on the reader object

for line in reader:
    id_revision = line[0]
...

Without the len&list function the iteration works, but when I calculate the number of row the iteration doesn't even begin.(Process finish without error)

edited Jun 12 '19 at 10:27

BPDESILVA

2,040
5
15
35

asked Jun 12 '19 at 10:14

Domenico Antonio Tropeano

does size mean how much space the file takes up in the file system? also `len(list(reader))` tells you the number of lines in csv, also `for line in reader` already iterates over each line, why do you need to do `total_line = len(list(reader))` for it? – Devesh Kumar Singh Jun 12 '19 at 10:16
No for size I mean the number of rows. Anyway I have edited the question – Domenico Antonio Tropeano Jun 12 '19 at 10:19
does this help? https://stackoverflow.com/questions/27504056/row-count-in-a-csv-file – Devesh Kumar Singh Jun 12 '19 at 10:22
Actually yes. data = list(reader) total_line = len(data) for line in data:....<\code> With this code works. – Domenico Antonio Tropeano Jun 12 '19 at 10:29

How to find size of a csv and either be able to iterate on the reader object

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