7stud wrote:
> On May 25, 12:49 pm, cjl <[EMAIL PROTECTED]> wrote:
>> reader = csv.reader(open('somefile.csv'))
>> for row in reader:
>> do something
>>
>> Any way to determine the "length" of the reader (the number of rows)
>> before iterating through the rows?
No. You have to read the records to know the length:
rows = list(reader)
print len(rows)
for row in rows:
# ...
> How about:
>
> f = open("somefile.csv")
> numlines = len(f.readlines())
No, a field in a csv file may contain newlines:
>>> import csv
>>> csv.writer(open("tmp.csv", "w")).writerows([["a", "b\nc"], ["d", "e"]])
>>> len(open("tmp.csv").readlines())
3 # number of lines
>>> len(list(csv.reader(open("tmp.csv"))))
2 # number of records
Peter
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