Question

Along the lines of my previous question, how can i join a list of strings into a string such that values get quoted cleanly. Something like:

['a', 'one 'two' three', 'foo, bar', '''both'''''] 

into:

a, 'one 'two' three', 'foo, bar', 'both\''' 

I suspect that the csv module will come into play here, but i’m not sure how to get the output I want.

Answer 1

Using the csv module you can do that way:

import csv writer = csv.writer(open('some.csv', 'wb')) writer.writerow(the_list) 

If you need a string just use StringIO instance as a file:

f = StringIO.StringIO() writer = csv.writer(f) writer.writerow(the_list) print f.getvalue() 

The output: a,'one ''two'' three','foo, bar','both''''

csv will write in a way it can read back later. You can fine-tune its output by defining a dialect, just set quotechar, escapechar, etc, as needed:

class SomeDialect(csv.excel):     delimiter = ','     quotechar = '''     escapechar = '\\'     doublequote = False     lineterminator = '\n'     quoting = csv.QUOTE_MINIMAL  f = cStringIO.StringIO() writer = csv.writer(f, dialect=SomeDialect) writer.writerow(the_list) print f.getvalue() 

The output: a,one \'two\' three,'foo, bar',both\''

The same dialect can be used with csv module to read the string back later to a list.