defchange_dir(destination):

try:

cwd=os.getcwd()

os.chdir(destination)

finally:

os.chdir(cwd)

withchange_dir('Sample-Dir-One'):

print(os.listdir())

withchange_dir('Sample-Dir-Two'):

print(os.listdir())

Lorem ipsum dolor sit amet, consectetur adipiscing elit.

class Open_File():

def __init__(self, destination):

pass

def __enter__(self):

pass

def __exit__(self, exc_type, exc_val, traceback):

pass

#### Using contextlib ####

@contextmanager

def open_file(file, mode):

f = open(file, mode)

yield f

f.close()

with open_file('sample.txt', 'w') as f:

f.write('Lorem ipsum dolor sit amet, consectetur adipiscing elit.')

print(f.closed)

#### CD Example ####

cwd = os.getcwd()

os.chdir('Sample-Dir-One')

print(os.listdir())

os.chdir(cwd)

cwd = os.getcwd()

os.chdir('Sample-Dir-Two')

print(os.listdir())

os.chdir(cwd)