Fwd: Formatting question.

mike5160 mike5160 at gmail.com
Wed Nov 21 17:17:05 CET 2007


On Nov 20, 9:13 pm, "Sergio Correia" <sergio.corr... at gmail.com> wrote:
> Hey Mike,
> Welcome to Python!
>
> About your first issue, just change the line
> outfile.write( "'%s'," % (LoL[x][y]))
> With
> outfile.write( "'%s'," % (LoL[x][y][:-1]))
>
> Why? Because when you do the line.split, you are including the '\n' at
> the end, so a new line is created.
>
> Now, what you are doing is not very pythonic (batteries are included
> in python, so you could just use the CSV module). Also, the for x in
> range(len(somelist)) is not recommended, you can just do something
> like:
>
> ========================
> import csv
>
> infile = open("mydata.txt", "rb")
> outfile = open("out.txt", "wb")
>
> reader = csv.reader(infile, delimiter='\t')
> writer = csv.writer(outfile, quotechar=None, delimiter = "\\")
>
> for row in reader:
>     data = "'" + "', '".join(row) + "'"
>     base = " ( Insert NBUSER.Grochamber Values %s, )"
>     writer.writerow([base % data])
>
> infile.close()
> outfile.close()
> ========================
> The above lines works like your program, writing exactly what you asked.
> Again, all lists are iterable, you don't need to iterate an integer
> from 1 to len(list). (isn't python wonderful?)
>
> HTH,
> Sergio
>
> On Nov 20, 2007 6:11 PM, mike5160 <mike5...74 at gmail.com> wrote:
>
> > Hi all,
>
> > My input file looks like this : ( the data is separated by tabs )
>
> > 11/26/2007      56.366  898.90  -10.086 23.11   1212.3
> > 11/26/2007      52.25   897.6   -12.5   12.6    13333.5
> > 11/26/2007      52.25   897.6   -12.5   12.6    133.5
>
> > The output I'm trying to get is as follows :
>
> >  ( Insert NBUSER.Grochamber Values
> > '11/26/2007','56.366','898.90','-10.086','23.11','1212.3', )
> >  ( Insert NBUSER.Grochamber Values
> > '11/26/2007','52.25','897.6','-12.5','12.6','13333.5', )
> >  ( Insert NBUSER.Grochamber Values
> > '11/26/2007','52.25','897.6','-12.5','12.6','133.5', )
>
> > The following is the program i have written so far :
>
> > LoL = []
>
> > for line in open('mydata.txt'):
> >     LoL.append(line.split("\t"))
>
> > print "read from a file: ", LoL,
>
> > outfile = open("out.dat", "w")
>
> > lilength = len(LoL)
> > liwidelength = len(LoL[1])
>
> > print "length of list is " , lilength, "long"
> > print "length of list is " , liwidelength, "long"
>
> > for x in range(lilength):
> >     outfile.write(" ( ")
> >     outfile.write('Insert NBUSER.Grochamber Values ')
> >     for y in range(liwidelength):
> >         outfile.write( "'%s'," % (LoL[x][y]))
> >     outfile.write(" ) \n")
>
> > outfile.close()
>
> > I have 3 questions :
>
> > 1. The formatting in the first line comes out wrong all the time. I m
> > using windows python 2.5.1. The last part of the first line is always
> > on the second line.
>
> > 2. How do I avoid the "," symbol after the last entry in the line?
> > (this are supposed to be sql-queries - importing excel based tabbed
> > data to sql database)
>
> > 3. What do I do when the data is missing? Like missing data?
>
> > Thanks for all your help!
>
> > Mike
>
> > --
> >http://mail.python.org/mailman/listinfo/python-list76

HI Sergio,

First of all, thanks for your reply and yes I'm new to Python.
Did a google on CSV and I am reading the documentation about it right
now. In the post I mentioned I was using Windows. I also have a laptop
with linux installed on it. When I ran the same program on my linux
laptop I did see the \n included in the list. Somehow, I did not see
it on windows, or missed it. So that cleared up the first problem.
Also, I will be doing a lot of this data importing from excel etc. can
you point me to a tutorial/document/book etc. where I can find
snippets of using various python utilities. For eg. something which
has the sample for using "line.split("\t") " or "
outfile.write( "'%s'," % (LoL[x][y][:-1])) " , explaining the various
options available. The default "Idle  gui help" is not too informative
to a newbie like me.

Thanks again for your reply,
Mike.



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