import argparse
import copy

a = argparse.Namespace(x=[1])
b = argparse.Namespace(**vars(a))
c = argparse.Namespace(**{k: copy.deepcopy(v) for k, v in vars(a).items()})

# b is wrong
b.x.append(2)
print(a.x)

# c makes deepcopy
a.x.append(3)
print(c.x)  # should only print out [1]