[Tutor] csv files

[Lloyd Kvam]

Sorry, two OBVIOUS typos.  There could be more.

On Sat, 2004-04-17 at 15:06, Lloyd Kvam wrote:
> Here are some suggestions for rewriting the process function:
> 
> change inp1,inp2,... to a list.  I'll call it inplist from here on.
> 
> Keep the 76 line assumption for now.
> 
> curlines = [inp.readline() for inp in inplist] 
> # read files in parallel into a list of current lines
> 
> outdata = [line[88:96] for line in curlines] 
> # pull out data from each line
CHANGED to outdata
> 
> outlabel = '"' + curlines[0][:12] + '"' 
> # pull out the lable value from first line and add quotes
> # that line is not so readable, but I think it is OK
> 
> outstring = ','.join([outlabel] + outdata)
> # make label + data into a list.
> # make the list into a string with comma separators

outdata is already a list.  It doesn't need square brackets to enclose
it.  outlabel is "listified" by putting it in square brackets.  +
combines two lists into one longer list.

> 
> Now you can write the string to the output file.
> 
> use the same kind of logic for outp2.  Notice that the four lines above
> would be exactly the same for outp2 except for the slice values 88:96
> and 123:130.  So rather than cutting and pasting those lines and
> changing the slice value, you could make them into a function that
> returns the string to be written.
> 
> To call process with a list of input files:
> process([inp1,inp2,inp3,inp4,inp5,inp6,inp7,inp8,inp9,inp10],outp1,outp2)
> simply put [] square brackets around the input files.
> 
> I used the list comprehension syntax for processing the inplist.  Though
> it may look a little strange as compared to C or Java code, it is a very
> nice syntax for making new lists from existing lists.
> 
> Note that you never use the csv module.  It doesn't look like you need
> it for this problem.
> 
> 
> On Fri, 2004-04-16 at 20:39, ABDUL JABBAR SIDDIQUE wrote:
> > As I mentioned in my last mail that I am new to programming and may
> > ask stupid questions. :)Bare with me please.
> > 
> > I have coded as follows to convert some text files into csv format for
> > onward reading into python programming. It seems that there must be
> > some short way to do all this which I don't know. I will
> > appreciate your advices. Following is the code:
> > 
> > from csv import *
> > 
> > def
> > process(inp1,inp2,inp3,inp4,inp5,inp6,inp7,inp8,inp9,inp10,outp1,outp2):   
> >     for i in range(76):    # it means i from 0 to 75
> >         line1=inp1.readline()
> >         line2=inp2.readline()
> >         line3=inp3.readline()
> >         line4=inp4.readline()
> >         line5=inp5.readline()
> >         line6=inp6.readline()
> >         line7=inp7.readline()
> >         line8=inp8.readline()
> >         line9=inp9.readline()
> >         line10=inp10.readline()
> >             
> >         if i >= 5:          ### Data values begin from line 5
> >            
> > outp1.write(('"'+line1[:12]+'"'+','+line1[88:96]+','+line2[88:96]+','+line3[88:96]+','+line4[88:96]+',' \
> >                        
> > +line5[88:96]+','+line6[88:96]+','+line7[88:96]+','+line8[88:96]+',' \
> >                         +line9[88:96]+','+line10[88:96])+"\n")  ###
> > Data values for Control Delays (MOE) is written to output file
> > 
> >            
> > outp2.write(('"'+line1[:12]+'"'+','+line1[123:130]+','+line2[123:130]+','+line3[123:130]+','+line4[123:130]+',' \
> >                        
> > +line5[123:130]+','+line6[123:130]+','+line7[123:130]+','+line8[123:130]+',' \
> >                         +line9[123:130]+','+line10[123:130])+"\n")
> >               ### Data values for Speed (MOE) is written to output
> > file
> > 
> > inp1 = open("S_1.OUT","r")      ### Results of Simulation output are
> > named as S_1.OUT, S_2.OUT etc.
> > inp2 = open("S_2.OUT","r")
> > inp3 = open("S_3.OUT","r")
> > inp4 = open("S_4.OUT","r")
> > inp5 = open("S_5.OUT","r")
> > inp6 = open("S_6.OUT","r")
> > inp7 = open("S_7.OUT","r")
> > inp8 = open("S_8.OUT","r")
> > inp9 = open("S_9.OUT","r")
> > inp10 = open("S_10.OUT","r")
> > 
> > outp1 = open ("CD.csv","w")
> > outp2 = open ("Speed.csv","w")
> > 
> > 
> > process(inp1,inp2,inp3,inp4,inp5,inp6,inp7,inp8,inp9,inp10,outp1,outp2)
> > 
> > 
> > print "data copied to file..."        ### Mentioning that process of
> > data extraction is completed.
> > 
> > # Now close the files
> > inp1.close()
> > inp2.close()
> > inp3.close()
> > inp4.close()
> > inp5.close()
> > inp6.close()
> > inp7.close()
> > inp8.close()
> > inp9.close()
> > inp10.close()
> > ### Finally output file is closed.
> > outp1.close()
> > outp2.close()
> > 
> > Jabbar
> > 
> > 
> > 
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> > 
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Lloyd Kvam
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