parse a csv file into a text file

[Zhen Zhang]

On Wednesday, February 5, 2014 7:34:57 PM UTC-5, MRAB wrote:
> On 2014-02-06 00:10, Zhen Zhang wrote:
> 
> > Hi, every one.
> 
> >
> 
> > I am a second year EE student.
> 
> > I just started learning python for my project.
> 
> >
> 
> > I intend to parse a csv file with a format like
> 
> >
> 
> > 3520005,"Toronto (Ont.)",C  ,F,2503281,2481494,F,F,0.9,1040597,979330,630.1763,3972.4,1
> 
> > 2466023,"Montréal (Que.)",V  ,F,1620693,1583590,T,F,2.3,787060,743204,365.1303,4438.7,2
> 
> > 5915022,"Vancouver (B.C.)",CY ,F,578041,545671,F,F,5.9,273804,253212,114.7133,5039.0,8
> 
> > 3519038,"Richmond Hill (Ont.)",T  ,F,162704,132030,F,F,23.2,53028,51000,100.8917,1612.7,28
> 
> >
> 
> > into a text file like the following
> 
> >
> 
> > Toronto 2503281
> 
> > Montreal 1620693
> 
> > Vancouver 578041
> 
> >
> 
> > I am extracting the 1st and 5th column and save it into a text file.
> 
> >
> 
> > This is what i have so far.
> 
> >
> 
> >
> 
> > [code]
> 
> >
> 
> > import csv
> 
> > file = open('raw.csv')
> 
> > reader = csv.reader(file)
> 
> >
> 
> > f = open('NicelyDone.text','w')
> 
> >
> 
> > for line in reader:
> 
> >        f.write("%s %s"%line[1],%line[5])
> 
> >
> 
> > [/code]
> 
> >
> 
> > This is not working for me, I was able to extract the data from the csv file as line[1],line[5]. (I am able to print it out)
> 
> > But I dont know how to write it to a .text file in the format i wanted.
> 
> >
> 
> % is an operator. When used with a format string on its left, its
> 
> arguments go on its right. In the general case, those arguments should
> 
> be put in a tuple, although if there's only one argument and it's not a
> 
> tuple, you can write just that argument:
> 
> 
> 
>      f.write("%s %s" % (line[1], line[5]))
> 
> 
> 
> > Also, I have to process the first column eg, "Toronto (Ont.)" into "Toronto".
> 
> > I am familiar with the function find(), I assume that i could extract Toronto out of Toronto(Ont.) using "(" as the stopping character,
> 
> > but based on my research , I have no idea how to use it and ask it to return me the string(Toronto).
> 
> >
> 
> Use find to tell you the index of the "(" (if there isn't one then
> 
> it'll return -1) and then slice the string to get the part preceding it.
> 
> 
> 
> Another way is to use the "partition" method.
> 
> 
> 
> Also, have a look at the "strip"/"lstrip"/"rstrip" methods.
> 
> 
> 
> > Here is my question:
> 
> > 1:What is the data format for line[1], if it is string how come f.write()does not work. if it is not string, how do i convert it to a string?
> 
> > 2:How do i extract the word Toronto out of Toronto(Ont) into a string form using find() or other methods.
> 
> >
> 
> > My thinking is that I could add those 2 string together like c=a+' ' +b, that would give me the format i wanted.
> 
> > So i can use f.write() to write into a file  ;)
> 
> >
> 
> > Sorry if my questions sounds too easy or stupid.
> 
> >
> 
> > Thanks ahead
> 
> >
> 
> > Zhen
> 
> >

Thanks for the reply, especially the tuple parts,
I was not familiar with this data format, 
but i guess i should :)