Peter Otten wrote:
> 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
>
Did you try:
import crystal_ball
num_lines=crystal_ball(reader)
Sorry I couldn't resist.
-Larry
--
http://mail.python.org/mailman/listinfo/python-list
