On 29/08/2012 00:01, 9bizy wrote:> On Tuesday, 28 August 2012 23:49:54
UTC+1, MRAB wrote:
>> On 28/08/2012 23:34, 9bizy wrote:
>> > This is what I have to reproduce the challenge I am having below:
>> >
>> > import csv
>> > import struct
>> >
>> > data = []
>> >
>> > for Node in csv.reader(file('s_data.xls')):
>>
>> That tries to read the file as CSV, but, judging from the extension,
>> it's in Excel's format. You don't even use what is read, i.e. Node.
>>
>> > data.append(list((file('s_data.xls'))))
>> >
>> That opens the file again and 'list' causes it to read the file as
>> though it were a series of lines in a text file, which, as I've said,
>> it looks like it isn't. The list of 'lines' is appended to the list
>> 'data', so that's a list of lists.
>> >
>> > data = struct.unpack('!B4HH', data)
>> > print "s_data.csv: ", data
>> >
>> > I tries so many format for the struct.unpack but I got this errors:
>> >
>> > Traceback (most recent call last):
>> >
>> > data = struct.unpack('!B4HH', data)
>> > struct.error: unpack requires a string argument of length 11
>> >
>> [snip]
>> It's complaining because it's expecting a string argument but you're
>> giving it a list instead.
>
> How do I then convert data to a string argument in this case?
>
The question is: what are you trying to do?
If you're trying to read an Excel file, then you should be trying the
'xlrd' module. You can find it here: http://www.python-excel.org/
If your trying to 'decode' a binary file, then you should open it in
binary mode (with "rb"), read (some of) it as a byte string and then
pass it to struct.unpack.
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