what is the python code to transpose rows of data to columns separated by commas?

In theory, this is your code:

transposedArr = zip(*regularArray)

Select allOpen in new window

Sorry I am new to Python coding.

Is regularArray my file I am transposing?

transposedArr = zip(*regularArray)

Sorry, I did not understand that you were using a file from your question.

Your case is a little more complicated, because you are not simply transposing, you are agregating the information. zip(* will turn rows into columns and vice versa, but without the summarization you are requesting.
To do that, the simplest way is to do this:

filename = 'Q_28491431.txt'  #this a file containing the initial lines you had posted.
f = open(filename,'rt')
dataAgg = {}
for line in f.readlines():
	cols = line.split(',') #I have assumed this is a csv file, using , to separate columns
	if cols[0] in dataAgg.keys():
		dataAgg[cols[0]].append(cols[1]) 
	else:
		arr = []
		arr.append(cols[1])
		dataAgg[cols[0]] = arr

for item in dataAgg.keys():
	print item,',',dataAgg[item]

Select allOpen in new window

Please observe that this may not be the most "pythonic" way of doing it, but I think it is very clear if you understand other programming languages. If you want to write "pythonic" code, using what is state of art in python code, you need to read documentation and lots of books.

Hi Walter,

Thanks for your reply. I am getting this error when I run your code.

Traceback (most recent call last):
  File "test.py", line 10, in <module>
    arr.append(cols[1])
IndexError: list index out of range
hpc2879@qsbcomp1$

Thanks

your file entry should be like this to work:

TXN_ID,CAT_ID
123,45
123,42
123,56
222,10
455,22
455,11

Select allOpen in new window

Or you can change the split command to separate by space.

More especifically, use this line:
 

	cols = filter(None,line.split(' '))

Select allOpen in new window

instead of this line:

cols = line.split(',')

Select allOpen in new window

Hi Walter,

It worked. Just wondering how the output can be written to a file.

Thanks