Handling CSV Files in Python

Hi,

I am writing & reading to both csv files (using the csv module) and to MS SQL databases (using pymssql). By default, they use different numeric precision levels. Specifically, the csv module uses only 12 digits while the DB module uses 17 digits. I may at times need precision greater than 12 digits, but I won't need beyond 17 digits. So I can use the pymssql default. But mostly, I'd like to know how to adjust these precision levels so that I have some control over it.

Here is an example small code, but it's trivial to test out in whichever way you want:

==================
import csv
myWriter = csv.writer(sys.stdout)
myWriter.writerow ( ('whatever', 12.345678901234567890) )

==================

will yield:

testing, 12.3456789012
(12 digits, total)

I know that I could do some sort of manipulation line by line, however the data that I am going to save is quite large, both in having many columns (of varying types) and in having many rows.
I have read that python, by default, prints only to 12 decimal points precision. I am therefore hoping that is some sort of default that I can adjust, maybe with a command looking something like:

float.precision(17)

or something similar to change all print defaults to 17. Ideally, I'd like to change something global like that so that I can take a very large list of tuples and just do the following:

myWriter.writerows(myData)

and that's it.

I am not sure how this thread works, but if I am not automatically notified via the e-mail address I provided, could you please e-mail any response to this.is.mvw@gmail? I don't check python or linux web pages frequently, as I am normally not working with either at any developer level.

Thanks!
Mike

How i can write this using CSV as input will be in CSV file.

Input:

a = 1
b = 2
c = 3

Output
If i print a then it should give 1
If i print b then it should give 2
and so on..........

thanks

I came accross this code for perl:
http://sysbio.harvard.edu/csb/resources/computational/scriptome/Windows/...

perl -e " @cols=(1, -1, 2); while(<>) { s/\r?\n//; @F=split /\t/, $_; print join( qq~\t~, @F[@cols]), qq~\n~ } warn qq~\nChose columns ~, join( qq~, ~, @cols), qq~ for $. lines\n\n~ " all_cols > some_cols_chosen

and I am trying to get a python code that does the same and will allow me to write say only the first 13 columns from a csv file to a new file.

Thanks
Shawn

Hi !

I recently wrote a quick script to convert CSV files of the form: foo, bar, blah, blah into nice HTML displays. Here it is:

#!/usr/bin/python
# -*- coding: utf-8 -*-

# CSV to HTML Converter

# Amit K. Saha 

import csv
import sys

if len(sys.argv) < 2:
  print "Usage: ./csv-html.py  "
  print
  print
  exit(0)

# Open the CSV file for reading
reader = csv.reader(open(sys.argv[1]))

# Create the HTML file
f_html = open(sys.argv[2],"w");
f_html.write('')

for row in reader: # Read a single row from the CSV file
  f_html.write('');# Create a new row in the table
  for column in row: # For each column..
    f_html.write('' + column + '');
  f_html.write('')


f_html.write('')

Hope it is useful!