context_manager.py

from contextlib import contextmanager
# Context Manager using object
class ContextManager():
	def __init__(self, name):
		self.name = name

	def __enter__(self, ):
		print('nvtx_marker on for: {}'.format(self.name))
		return self

	def __exit__(self,exc_type, exc_value, exc_traceback):
		print("nvtx_marker off for: {}".format(self.name))

with ContextManager("path1") as manager:
	with ContextManager("path2") as manager:
		print("with statement block")

print("")
print("#########################################")
print("")

# context manager using decorator
@contextmanager
def ContextManager_alt(name):
	print("nvtx marker on for {}".format(name))
	yield
	print("nvtx marker off for {}".format(name))

with ContextManager_alt("path1") as manager:
	with ContextManager_alt("path2") as manager:
		print("with statement block")

Output:

nvtx_marker on for: path1
nvtx_marker on for: path2
with statement block
nvtx_marker off for: path2
nvtx_marker off for: path1

#########################################

nvtx marker on for path1
nvtx marker on for path2
with statement block
nvtx marker off for path2
nvtx marker off for path1