Re: Question on the csv library
2009/8/28 John Machin sjmac...@lexicon.net: Mark, there exist parallel universes the denizens of which use strange notation e.g. 1.234,56 instead of 1,234.56 When displaying data, sure. and would you believe they use ';' instead of ',' as a list separator ... CSV is a data transfer format, not a display format. Locale specific stuff like this has no place in it. Dates, IMHO, should be in the ugly but unambiguous ISO 8601 format in a CSV. It's for import and export, not for looking pretty. Besides - CSV; the clue's in the name. ;-) Excel perfidiously gives them what they expect rather than forcing them to comply with The One True Way. When people export to a comma separated value file, they are almost certainly expecting a file containing values separated by comas. If Excel isn't giving them this by default, it's broken. -- Cheers, Simon B. -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
John Machin wrote: On Aug 28, 6:44 am, Mark Lawrence breamore...@yahoo.co.uk wrote: vsoler wrote: On Aug 27, 9:42 pm, Andreas Waldenburger use...@geekmail.invalid 1- the csv file was generated with Excel 2007; no prompts for what the separator should be; Excel has used ; by default, without asking anything I find this difficult to believe, Mark, there exist parallel universes the denizens of which use strange notation e.g. 1.234,56 instead of 1,234.56 and would you believe they use ';' instead of ',' as a list separator ... Excel perfidiously gives them what they expect rather than forcing them to comply with The One True Way. I suggest a new file type csvewtlsinac i.e. comma seperated value except when the list seperator is not a comma.:) Does this cover everything? p.s. is it separator or seperator, after 50+ years I still can't remember? -- Kindest regards. Mark Lawrence. -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Fri, 28 Aug 2009 09:03:49 +0100 Mark Lawrence breamore...@yahoo.co.uk wrote: p.s. is it separator or seperator, after 50+ years I still can't remember? The former. It's cognate to English part if that helps any. /W -- INVALID? DE! -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Aug 27, 3:06 pm, vsoler vicente.so...@gmail.com wrote:
I am trying to read a csv file generated by excel.
Although I succeed in reading the file, the format that I get is not
suitable for me.
I've done:
import csv
spamReader = csv.reader(open('C:\\abc.csv', 'r'))
print spamReader
_csv.reader object at 0x01022E70
for row in spamReader:
print row
['codigo;nombre;cantidad']
['a;qwe;1']
['b;asd;2']
['c;zxc;3']
My questions are:
1- Why using print spamReader I cannot see the data?
I expected to see a list of lists, a kind of a matrix, but I get
nothing
2- Why are the rows in a single string?
I expected a list of fields that, when text, would be delimited by
To tell the truth, the file generated by excel does not contain the
strings delimited by . Isn't it weird?
3- Is there anything I can do to have my data in a list of lists
structure? would another kind of data suit better my needs?
Thank you for your help
Vicente Soler
the csv module can handle any delimiter.
change this spamReader = csv.reader(open('C:\\abc.csv', 'r'))
to this spamReader = csv.reader(open('C:\\abc.csv', 'r'),
delimiter=';')
hope this helps,
Steven Rumbalski
--
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Re: Question on the csv library
On Aug 28, 5:43 pm, Steven Rumbalski googleacco...@rumbalski.com
wrote:
On Aug 27, 3:06 pm, vsoler vicente.so...@gmail.com wrote:
I am trying to read a csv file generated by excel.
Although I succeed in reading the file, the format that I get is not
suitable for me.
I've done:
import csv
spamReader = csv.reader(open('C:\\abc.csv', 'r'))
print spamReader
_csv.reader object at 0x01022E70
for row in spamReader:
print row
['codigo;nombre;cantidad']
['a;qwe;1']
['b;asd;2']
['c;zxc;3']
My questions are:
1- Why using print spamReader I cannot see the data?
I expected to see a list of lists, a kind of a matrix, but I get
nothing
2- Why are the rows in a single string?
I expected a list of fields that, when text, would be delimited by
To tell the truth, the file generated by excel does not contain the
strings delimited by . Isn't it weird?
3- Is there anything I can do to have my data in a list of lists
structure? would another kind of data suit better my needs?
Thank you for your help
Vicente Soler
the csv module can handle any delimiter.
change this spamReader = csv.reader(open('C:\\abc.csv', 'r'))
to this spamReader = csv.reader(open('C:\\abc.csv', 'r'),
delimiter=';')
hope this helps,
Steven Rumbalski
Thank you very much for all your comments. After reading them I can
conclude that:
1- the CSV format is not standardized; each piece of software uses it
differently
2- the C in CSV does not mean comma for Microsoft Excel; the ;
comes from my regional Spanish settings
3- Excel does not even put quotes around litteral texts, not even when
the text contains a blank
But, perhaps, there is no standard alternative to CSV !!!
--
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Re: Question on the csv library
En Fri, 28 Aug 2009 13:35:19 -0300, vsoler vicente.so...@gmail.com escribió: On Aug 28, 5:43 pm, Steven Rumbalski googleacco...@rumbalski.com wrote: On Aug 27, 3:06 pm, vsoler vicente.so...@gmail.com wrote: I am trying to read a csv file generated by excel. ['a;qwe;1'] ['b;asd;2'] ['c;zxc;3'] Thank you very much for all your comments. After reading them I can conclude that: 1- the CSV format is not standardized; each piece of software uses it differently Yes! And that's part of the pain of working with 'csv' files. 2- the C in CSV does not mean comma for Microsoft Excel; the ; comes from my regional Spanish settings Yes - but not just Excel, other programs do call CSV files that are TAB-separated, by example. 3- Excel does not even put quotes around litteral texts, not even when the text contains a blank I guess you'll get quotes around text containing ';' characters But, perhaps, there is no standard alternative to CSV !!! Of course there are! You may use SYLK, DIFF, XML, XDR... The nice thing about standards is that there are so many to choose from. (Andrew S. Tanenbaum) But look for the xlrd package, it lets you read Excel files directly from Python. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
vsoler wrote: Thank you very much for all your comments. After reading them I can conclude that: 1- the CSV format is not standardized; each piece of software uses it differently True, but there are commonalities. See http://en.wikipedia.org/wiki/Comma-separated_values 2- the C in CSV does not mean comma for Microsoft Excel; the ; comes from my regional Spanish settings The C really does stand for comma. I've never seen MS spit out semi-colon separated text on a CSV format. 3- Excel does not even put quotes around litteral texts, not even when the text contains a blank There is no need to quote text literals with whitespace in them. There is a need when a newline exists or when the separator character is embedded in the field. --David -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
vsoler wrote:
On Aug 28, 5:43 pm, Steven Rumbalski googleacco...@rumbalski.com
wrote:
On Aug 27, 3:06 pm, vsoler vicente.so...@gmail.com wrote:
I am trying to read a csv file generated by excel.
Although I succeed in reading the file, the format that I get is not
suitable for me.
I've done:
import csv
spamReader = csv.reader(open('C:\\abc.csv', 'r'))
print spamReader
_csv.reader object at 0x01022E70
for row in spamReader:
print row
['codigo;nombre;cantidad']
['a;qwe;1']
['b;asd;2']
['c;zxc;3']
My questions are:
1- Why using print spamReader I cannot see the data?
I expected to see a list of lists, a kind of a matrix, but I get
nothing
2- Why are the rows in a single string?
I expected a list of fields that, when text, would be delimited by
To tell the truth, the file generated by excel does not contain the
strings delimited by . Isn't it weird?
3- Is there anything I can do to have my data in a list of lists
structure? would another kind of data suit better my needs?
Thank you for your help
Vicente Soler
the csv module can handle any delimiter.
change this spamReader = csv.reader(open('C:\\abc.csv', 'r'))
to this spamReader = csv.reader(open('C:\\abc.csv', 'r'),
delimiter=';')
hope this helps,
Steven Rumbalski
Thank you very much for all your comments. After reading them I can
conclude that:
1- the CSV format is not standardized; each piece of software uses it
differently
2- the C in CSV does not mean comma for Microsoft Excel; the ;
comes from my regional Spanish settings
3- Excel does not even put quotes around litteral texts, not even when
the text contains a blank
But, perhaps, there is no standard alternative to CSV !!!
This depends on the use case of yourself or your users. If you could
give more detail on what you are trying to achieve then I'm sure that
more help will be forthcoming. For example, could the file be saved in
Excel 97-2003 xls format and then processed with the excellent
xlrd/xlwt/xlutils? They are available here:-
http://pypi.python.org/pypi/xlutils/1.4.0
--
Kindest regards.
Mark Lawrence.
--
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Re: Question on the csv library
David Smith d...@cornell.edu writes: 2- the C in CSV does not mean comma for Microsoft Excel; the ; comes from my regional Spanish settings The C really does stand for comma. I've never seen MS spit out semi-colon separated text on a CSV format. That's because you're running MS Office in a US language environment. In almost all of Europe MS products use comma as the decimal separator, and semicolon for CSV field separation. -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Aug 29, 2:35 am, vsoler vicente.so...@gmail.com wrote: 3- Excel does not even put quotes around litteral texts, not even when the text contains a blank Correct. Quoting is necessary only if a text field contains a delimiter (semicolon/comma), a newline, or the quote character. You can read Excel CSV output using the Python csv module by specifying delimiter=; If you need to feed a CSV file to some software that demands that text fields be quoted unconditionally, you have at least two options: (1) If you know which fields should be text fields, you can read the Excel-output file with Python csv, convert your non-text fields to float, and write it back out with quoting=csv.QUOTE_NONNUMERIC. (2) If you want precise control (and thus precise knowledge), use xlrd (http://pypi.python.org/pypi/xlrd) to read Excel 97-2003 .xls files -- it will tell you cell by cell (NOT column by column (the user has control of the type at the cell level)) whether the cell contains text (reported as a unicode object), a number (float), a Boolean (int, 1 or 0), a date (float, days since ? (read the docs)), or an error code e.g. #DIV/0! (int, read the docs) ... then you can write it out however you like. HTH, John -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Thu, Aug 27, 2009 at 3:06 PM, vsoler vicente.so...@gmail.com wrote:
I am trying to read a csv file generated by excel.
Although I succeed in reading the file, the format that I get is not
suitable for me.
I've done:
import csv
spamReader = csv.reader(open('C:\\abc.csv', 'r'))
print spamReader
_csv.reader object at 0x01022E70
for row in spamReader:
print row
['codigo;nombre;cantidad']
['a;qwe;1']
['b;asd;2']
['c;zxc;3']
My questions are:
1- Why using print spamReader I cannot see the data?
I expected to see a list of lists, a kind of a matrix, but I get
nothing
It's because csv.reader does the same thing open does. It returns an
iterable, not a list. The file is opened but not processed until you
iterate through it. You cannot see the data when you do print
spamReader because of this and because the csv reader object does
define a __str__ method.
2- Why are the rows in a single string?
I expected a list of fields that, when text, would be delimited by
To tell the truth, the file generated by excel does not contain the
strings delimited by . Isn't it weird?
CSV stands for comma separated variables. It actually has nothing to
do with the quotes- they're just used in case an element has a comma
in it, so the reader knows it's a string literal and not a separate
column. Your comma separated variable worksheet seems to be semicolon
separated. That's why the reader isn't splitting it.
3- Is there anything I can do to have my data in a list of lists
structure? would another kind of data suit better my needs?
just do a list comprehension
sheet = [row for row in spamReader]
Thank you for your help
Vicente Soler
--
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--
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Re: Question on the csv library
On Thu, 27 Aug 2009 21:36:28 +0200 Andreas Waldenburger use...@geekmail.invalid wrote: [snip] Might I humbly suggest sheet = list(spamReader) # ? Oh, and while I'm humbly suggesting: spam_reader instead of spamReader or SpamReader or SpamrEadeR or suchlike. Caps are reserved for classes. Not a necessity, of course. But it's the dialect around these parts. /W -- INVALID? DE! -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Aug 27, 9:42 pm, Andreas Waldenburger use...@geekmail.invalid wrote: On Thu, 27 Aug 2009 21:36:28 +0200 Andreas Waldenburger use...@geekmail.invalid wrote: [snip] Might I humbly suggest sheet = list(spamReader) # ? Oh, and while I'm humbly suggesting: spam_reader instead of spamReader or SpamReader or SpamrEadeR or suchlike. Caps are reserved for classes. Not a necessity, of course. But it's the dialect around these parts. /W -- INVALID? DE! Thank you for your answers. Let me however make some comments: 1- the csv file was generated with Excel 2007; no prompts for what the separator should be; Excel has used ; by default, without asking anything 2- about capitalisation, I used the var spamReader because I just copy/pasted from the official python site: http://docs.python.org/library/csv.html 3- when I try sheet = [row for row in spamReader] print sheet [] all I get is an empty list; something seems not to be working properly Same result list: I get an empty list sheet = list(spamReader) Thank you again for your help, which is highly appreciated. Vicente Soler -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Thu, 27 Aug 2009 13:12:07 -0700 (PDT) vsoler vicente.so...@gmail.com wrote: On Aug 27, 9:42 pm, Andreas Waldenburger use...@geekmail.invalid wrote: [snip what I wrote] Thank you for your answers. Let me however make some comments: 1- the csv file was generated with Excel 2007; no prompts for what the separator should be; Excel has used ; by default, without asking anything Apparently it's possible, but it's a kludge http://astrochimp.com/2005/12/20/export-csv-with-any-delimiter/comment-page-1/ Anyways, ... 2- about capitalisation, I used the var spamReader because I just copy/pasted from the official python site: http://docs.python.org/library/csv.html Oh, switcheroo! Well, those hypocrites! 3- when I try sheet = [row for row in spamReader] print sheet [] all I get is an empty list; something seems not to be working properly Same result list: I get an empty list sheet = list(spamReader) Thank you again for your help, which is highly appreciated. I'm assuming you do that after you've iterated over the file before? Because it did work in a previous post of yours. Here's the deal: When you iterate over a file (or read from it in any other manner) you advance in the file. After iteration, you're at the end, of course. So iterating again yields silch. Hmm ... don't know how that translates to a CSVReader. But I postulate that it'l work on a fresh run. /W -- INVALID? DE! -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
vsoler wrote: On Aug 27, 9:42 pm, Andreas Waldenburger use...@geekmail.invalid wrote: On Thu, 27 Aug 2009 21:36:28 +0200 Andreas Waldenburger use...@geekmail.invalid wrote: [snip] Might I humbly suggest sheet = list(spamReader) # ? Oh, and while I'm humbly suggesting: spam_reader instead of spamReader or SpamReader or SpamrEadeR or suchlike. Caps are reserved for classes. Not a necessity, of course. But it's the dialect around these parts. /W -- INVALID? DE! Thank you for your answers. Let me however make some comments: 1- the csv file was generated with Excel 2007; no prompts for what the separator should be; Excel has used ; by default, without asking anything I find this difficult to believe, but assuming that you are correct then use the delimiter=';' argument in the call to csv.reader. See the csv module documentation section Dialects and Formatting Parameters for more information. 2- about capitalisation, I used the var spamReader because I just copy/pasted from the official python site: http://docs.python.org/library/csv.html 3- when I try sheet = [row for row in spamReader] print sheet [] all I get is an empty list; something seems not to be working properly Same result list: I get an empty list sheet = list(spamReader) Thank you again for your help, which is highly appreciated. Vicente Soler -- Kindest regards. Mark Lawrence. -- http://mail.python.org/mailman/listinfo/python-list
Re: Question on the csv library
On Aug 28, 6:44 am, Mark Lawrence breamore...@yahoo.co.uk wrote: vsoler wrote: On Aug 27, 9:42 pm, Andreas Waldenburger use...@geekmail.invalid 1- the csv file was generated with Excel 2007; no prompts for what the separator should be; Excel has used ; by default, without asking anything I find this difficult to believe, Mark, there exist parallel universes the denizens of which use strange notation e.g. 1.234,56 instead of 1,234.56 and would you believe they use ';' instead of ',' as a list separator ... Excel perfidiously gives them what they expect rather than forcing them to comply with The One True Way. -- http://mail.python.org/mailman/listinfo/python-list
