try:
kv = {1: 'php', 2: 'python', 3: 'java'}
print(kv[1])
except KeyError as e:
print('key not found')
else:
raise ValueError()
'''
run:
php
Traceback (most recent call last):
File "C:/python/filename.python", line 8, in <module>
raise ValueError()
ValueError
'''