I wanted to sort column 2 in assending order and I read whole file in array
"data" and did the following:
data.sort(key = lambda fields:(fields[2]))
I have sorted column 2, however I want to count the numbers in the column 2.
i.e. I want to know, for example, how many repeates of say '3' (first row,
2nd column in above data) are there in column 2.
I think you're trying to count in the wrong step -- I'd do the
counting while you read the file in; not while you're trying to
sort. Maybe something like this untested file-wrapper:
class Histo:
def __init__(self, data, column):
self.data = data
self.column = column
self.stats = defaultdict(int)
self.exhausted = False
def __iter__(self):
if self.exhausted:
raise StopIteration("Input exhausted")
for line in self.data:
self.stats[line[self.column]] += 1
yield line
self.exhausted = True
def stats_so_far(self):
return self.stats
with file('in.txt') as f:
r = csv.reader(f, delimiter='\t')
h = Histo(r, 2)
data = list(h) # slurp up the elements
print repr(h.stats_so_far())
data.sort(key = lambda fields: (fields[2]))
-tkc
--
http://mail.python.org/mailman/listinfo/python-list
