Hi Gharg, this is expected, both because your program would not actually receive `--boolean=''` but `--boolean=`:

➜  ~ cat test.py
import sys

print(sys.argv)
➜  ~ python test.py --boolean=''
['test.py', '--boolean=']

and the way the type argument works. 

You can do what you are looking for by using:

➜  ~ cat test.py
import argparse

parser = argparse.ArgumentParser()
parser.add_argument('--boolean', action='store_const', const=True, default=False)

print(parser.parse_args())
➜  ~ python test.py --boolean
Namespace(boolean=True)
➜  ~ python test.py
Namespace(boolean=False)