In [1]:

    

import re


    

In [2]:

    

s = 'aaa@xxx.com'


    

In [3]:

    

m = re.match(r'[a-z]+@[a-z]+\.[a-z]+', s)
print(m)


    

    




<re.Match object; span=(0, 11), match='aaa@xxx.com'>

In [4]:

    

print(type(m))


    

    




<class 're.Match'>

In [5]:

    

print(m.start())


    

    




0

In [6]:

    

print(m.end())


    

    




11

In [7]:

    

print(m.span())


    

    




(0, 11)

In [8]:

    

print(m.group())


    

    




aaa@xxx.com

In [9]:

    

print(type(m.group()))


    

    




<class 'str'>

In [10]:

    

m = re.match(r'([a-z]+)@([a-z]+)\.([a-z]+)', s)
print(m)


    

    




<re.Match object; span=(0, 11), match='aaa@xxx.com'>

In [11]:

    

print(m.groups())


    

    




('aaa', 'xxx', 'com')

In [12]:

    

print(m.group())


    

    




aaa@xxx.com

In [13]:

    

print(m.group(0))


    

    




aaa@xxx.com

In [14]:

    

print(m.group(1))


    

    




aaa

In [15]:

    

print(m.group(2))


    

    




xxx

In [16]:

    

print(m.group(3))


    

    




com

In [17]:

    

# print(m.group(4))
# IndexError: no such group


    

In [18]:

    

print(m.group(0, 1, 3))


    

    




('aaa@xxx.com', 'aaa', 'com')

In [19]:

    

print(m.span())


    

    




(0, 11)

In [20]:

    

print(m.span(3))


    

    




(8, 11)

In [21]:

    

# print(m.span(4))
# IndexError: no such group


    

In [22]:

    

# print(m.span(0, 1))
# TypeError: span expected at most 1 arguments, got 2


    

In [23]:

    

m = re.match(r'(([a-z]+)@([a-z]+)\.([a-z]+))', s)
print(m)


    

    




<re.Match object; span=(0, 11), match='aaa@xxx.com'>

In [24]:

    

print(m.groups())


    

    




('aaa@xxx.com', 'aaa', 'xxx', 'com')

In [25]:

    

m = re.match(r'(?P<local>[a-z]+)@(?P<SLD>[a-z]+)\.(?P<TLD>[a-z]+)', s)
print(m)


    

    




<re.Match object; span=(0, 11), match='aaa@xxx.com'>

In [26]:

    

print(m.group('local'))


    

    




aaa

In [27]:

    

print(m.group('SLD'))


    

    




xxx

In [28]:

    

print(m.group('TLD'))


    

    




com

In [29]:

    

print(m.group(0))


    

    




aaa@xxx.com

In [30]:

    

print(m.group(3))


    

    




com

In [31]:

    

print(m.group(0, 2, 'TLD'))


    

    




('aaa@xxx.com', 'xxx', 'com')

In [32]:

    

print(m.groups())


    

    




('aaa', 'xxx', 'com')

In [33]:

    

print(m.groupdict())


    

    




{'local': 'aaa', 'SLD': 'xxx', 'TLD': 'com'}

In [34]:

    

print(type(m.groupdict()))


    

    




<class 'dict'>

In [35]:

    

print(re.match(r'[a-z]+@[a-z]+\.[a-z]+', s))


    

    




<re.Match object; span=(0, 11), match='aaa@xxx.com'>

In [36]:

    

print(bool(re.match(r'[a-z]+@[a-z]+\.[a-z]+', s)))


    

    




True

In [37]:

    

print(re.match('[0-9]+', s))


    

    




None

In [38]:

    

print(bool(re.match('[0-9]+', s)))


    

    




False

In [39]:

    

if re.match(r'[a-z]+@[a-z]+\.[a-z]+', s):
    print('match')
else:
    print('no match')


    

    




match

In [40]:

    

if re.match('[0-9]+', s):
    print('match')
else:
    print('no match')


    

    




no match

In [41]:

    

m = re.match('[0-9]*', s)
print(m)


    

    




<re.Match object; span=(0, 0), match=''>

In [42]:

    

print(m.group() == '')


    

    




True

In [43]:

    

print(bool(m))


    

    




True

In [44]:

    

if re.match('[0-9]*', s):
    print('match')
else:
    print('no match')


    

    




match