Method for guessing type of data represented currently represented as strings

Question

I'm currently parsing CSV tables and need to discover the "data types" of the columns. I don't know the exact format of the values. Obviously, everything that the CSV parser outputs is a string. The data types I am currently interested in are:

1. integer
2. floating point
3. date
4. boolean
5. string

My current thoughts are to test a sample of rows (maybe several hundred?) in order to determine the types of data present through pattern matching.

I am particularly concerned about the date data type - is their a python module for parsing common date idioms (obviously I will not be able to detect them all)?

What about integers and floats?

Answer 1

ast.literal_eval() can get the easy ones.

Answer 2

Dateutil comes to mind for parsing dates.

For integers and floats you could always try a cast in a try/except section

>>> f = "2.5"
>>> i = "9"
>>> ci = int(i)
>>> ci
9
>>> cf = float(f)
>>> cf
2.5
>>> g = "dsa"
>>> cg = float(g)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for float(): dsa
>>> try:
...   cg = float(g)
... except:
...   print "g is not a float"
...
g is not a float
>>>