1: + 比 * 效果不好

import re

def is_valid_email(addr):
if re.match(r'^[\d\w\.]+@[\d\w]+\.com',addr):
return True
else:
return False

# 测试:
assert is_valid_email('someone@gmail.com')
assert is_valid_email('bill.gates@microsoft.com')
assert not is_valid_email('bob#example.com')
assert not is_valid_email('mr-bob@example.com')
print('ok')

Homework2:

import re

def name_of_email(addr):
m = re.match(r'^<?(\w+\s*\w*)>?(\s*\w*)@(\w+).(\w+)', addr)
if m:
return m.group(1)
else:
return None

# 测试:
assert name_of_email('<Tom Paris> tom@voyager.org') == 'Tom Paris'
assert name_of_email('tom@voyager.org') == 'tom'
print('ok')

> 右边有个\s我是没想到的