Read specific columns in csv using python

Question

I have a csv file that look like this:

+-----+-----+-----+-----+-----+-----+-----+-----+
| AAA | bbb | ccc | DDD | eee | FFF | GGG | hhh |
+-----+-----+-----+-----+---         


        

Answer 1

def read_csv(file, columns, type_name="Row"):
  try:
    row_type = namedtuple(type_name, columns)
  except ValueError:
    row_type = tuple
  rows = iter(csv.reader(file))
  header = rows.next()
  mapping = [header.index(x) for x in columns]
  for row in rows:
    row = row_type(*[row[i] for i in mapping])
    yield row

Example:

>>> import csv
>>> from collections import namedtuple
>>> from StringIO import StringIO
>>> def read_csv(file, columns, type_name="Row"):
...   try:
...     row_type = namedtuple(type_name, columns)
...   except ValueError:
...     row_type = tuple
...   rows = iter(csv.reader(file))
...   header = rows.next()
...   mapping = [header.index(x) for x in columns]
...   for row in rows:
...     row = row_type(*[row[i] for i in mapping])
...     yield row
... 
>>> testdata = """\
... AAA,bbb,ccc,DDD,eee,FFF,GGG,hhh
... 1,2,3,4,50,3,20,4
... 2,1,3,5,24,2,23,5
... 4,1,3,6,34,1,22,5
... 2,1,3,5,24,2,23,5
... 2,1,3,5,24,2,23,5
... """
>>> testfile = StringIO(testdata)
>>> for row in read_csv(testfile, "AAA GGG DDD".split()):
...   print row
... 
Row(AAA='1', GGG='20', DDD='4')
Row(AAA='2', GGG='23', DDD='5')
Row(AAA='4', GGG='22', DDD='6')
Row(AAA='2', GGG='23', DDD='5')
Row(AAA='2', GGG='23', DDD='5')