python: int and long are unified

Since Python 2.4, int and long are unified. Furthermore, from Python 3, int is the only type for integer, which has the capacity of long in Python 2.

sys.maxint returns the maximum integer number that Python can hold.

see also

• How does Python manage int and long?

python: parse boolean from string

def parse_bool(s):
    return s.lower() in ("yes", "true", "T", "1")

NOTE:

bool('foo') # True
bool('') # False

You can not use the above function to parse boolean from string.

python: check if a variable is a integer

if isinstance(var, int):
    print("It is integer")

On python 2:

if is instance(var, (int, long)):
    print("It is integer")

python: check if a variable is a string

import sys

if isinstance(var, basestring if sys.version_info[0]<3 else str):
    print("it is string") # var is string

see also

• stackoverflow

Python: check argument type

• for objects:

  def f(arg):
      if isinstance(arg, ClassA):
          print('A')
      elif isintance(arg, ClassB):
          print('B')
      elif issubclass(arg, ClassC):
          print('subclass of C')
      else:
          print("D")
  

• for built-in types:

  def f(arg):
      if type(arg) is str:
          print "str"
      elif type(arg) is int:
          print "int"
      elif type(arg) is dict:
          print "dict"
      else:
          print "unsupported"