Writing csv with python

Question

I wrote a python script in which I generate a csv from numbers I computed.

The rows I write are:

writeRow = [str(t), len(c) , {k for k in c.keys()}, {k for k in c.values()}]

I have two problems:

t is a number that can begin by 0. But in that case, the 0 is deleted. I tried without str() but it doesn't change...
the sets are printed as sets in the cells. However, I want to write these numbers separated by commas in the same cell and without the {} How can I do that?

edit

I am using the csv module; In the code, I create lists for each row to write and then write them with csv.writerow

I'm gonna post more code:

from csv import reader, writer
with open(fileName1) as inp, open(fileName2,'w') as o:

I then define the reader, writer, and the variables t,c

writeRow = [str(t), len(c) , {k for k in c.keys()}, {k for k in c.values()}]

Then I write the result in the output file

Edit form of t and what a row should look like

t = 023 t = 123 t is an int

The line in the end should look like:

cell1  cell2         cell3       cell4 
123    2     string1,string2    num1,num2

string1 and str2 are the dict keys; num1,num2 the corresponding values

Actually this is what I do. In the code, I create lists for each row to write and then write them with csv.writerow — teaLeef
– teaLeef, Commented Oct 31, 2013 at 21:51
Please post a line as you want it to be rendered. Do you have to same amount of columns (len(c)) for each row? CSV does not fit very well otherwise. — Kijewski
– Kijewski, Commented Oct 31, 2013 at 21:55
I think you'd be wise to show more code. I'm not sure what your point 1 means. t can begin with zero? — ForeverWintr
– ForeverWintr, Commented Oct 31, 2013 at 21:55
What is type(t)? Is it a str that represents a number? Is 076 supposed to be octal? 076 == 62. — Kijewski
– Kijewski, Commented Oct 31, 2013 at 21:58

Alexander L. Belikoff · Accepted Answer · 2013-10-31 22:00:47Z

2

For starters, you can take advantage of the join() method (assuming keys and values are strings):

",".join(c.keys()) + "," + ",".join(c.values())

This will take care of commas. However, this will break very easily for any non-trivial data, so consider using csv module instead, which would take care of escaping dangerous characters.

edited Oct 31, 2013 at 22:00

answered Oct 31, 2013 at 21:52

Alexander L. Belikoff

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1 Comment

teaLeef Over a year ago

This returns in each cell d,i,c,t,_,k,e,y,s,(key_names)

desired login · Accepted Answer · 2013-10-31 22:27:49Z

1

Use string formatting for the padding with 0s, and join for the sets:

writeRow = ['{:0>3}'.format(t), len(c) , ','.join(c.keys()), ','.join(c.values())]

note that you should not enter your value for t with a leading 0:

>>>t = 023
>>>t
19

answered Oct 31, 2013 at 22:27

desired login

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Comments

DanHickstein · Accepted Answer · 2013-10-31 21:55:13Z

1

What about using format strings?

'%s,%i'%(t,c)

might do what you want. You could also use '%03i' or something similar to produce some padding zeros before your number. Or, I might misunderstand your question. Try posting a more complete (runnable) example.

answered Oct 31, 2013 at 21:55

DanHickstein

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1 Comment

teaLeef Over a year ago

I think my question was not clear (I edited it with an example)

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