>>> import re
>>> s = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}"
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> seeker = re.compile("[abcDEF4]")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(0, 1), match='a'>
<re.Match object; span=(1, 2), match='b'>
<re.Match object; span=(2, 3), match='c'>
<re.Match object; span=(29, 30), match='D'>
<re.Match object; span=(30, 31), match='E'>
<re.Match object; span=(31, 32), match='F'>
<re.Match object; span=(56, 57), match='4'>
>>> for k in seeker.finditer(s):
...     print(k.span())
... 
(0, 1)
(1, 2)
(2, 3)
(29, 30)
(30, 31)
(31, 32)
(56, 57)
>>> for k in seeker.finditer(s):
...     print(k.group())
... 
a
b
c
D
E
F
4
>>> seeker = re.compile("[a-z]")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(0, 1), match='a'>
<re.Match object; span=(1, 2), match='b'>
<re.Match object; span=(2, 3), match='c'>
<re.Match object; span=(3, 4), match='d'>
<re.Match object; span=(4, 5), match='e'>
<re.Match object; span=(5, 6), match='f'>
<re.Match object; span=(6, 7), match='g'>
<re.Match object; span=(7, 8), match='h'>
<re.Match object; span=(8, 9), match='i'>
<re.Match object; span=(9, 10), match='j'>
<re.Match object; span=(10, 11), match='k'>
<re.Match object; span=(11, 12), match='l'>
<re.Match object; span=(12, 13), match='m'>
<re.Match object; span=(13, 14), match='n'>
<re.Match object; span=(14, 15), match='o'>
<re.Match object; span=(15, 16), match='p'>
<re.Match object; span=(16, 17), match='q'>
<re.Match object; span=(17, 18), match='r'>
<re.Match object; span=(18, 19), match='s'>
<re.Match object; span=(19, 20), match='t'>
<re.Match object; span=(20, 21), match='u'>
<re.Match object; span=(21, 22), match='v'>
<re.Match object; span=(22, 23), match='w'>
<re.Match object; span=(23, 24), match='x'>
<re.Match object; span=(24, 25), match='y'>
<re.Match object; span=(25, 26), match='z'>
>>> seeker = re.compile("[\[]")
>>> for k in seeker.finditer(s):
...     print(k)
... 
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> seeker = re.compile("[^a-zA-Z0-9]")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(63, 64), match='!'>
<re.Match object; span=(64, 65), match='@'>
<re.Match object; span=(65, 66), match='#'>
<re.Match object; span=(66, 67), match='$'>
<re.Match object; span=(67, 68), match='%'>
<re.Match object; span=(68, 69), match='^'>
<re.Match object; span=(69, 70), match='&'>
<re.Match object; span=(70, 71), match='*'>
<re.Match object; span=(71, 72), match='('>
<re.Match object; span=(72, 73), match=')'>
<re.Match object; span=(73, 74), match='_'>
<re.Match object; span=(74, 75), match='+'>
<re.Match object; span=(75, 76), match='{'>
<re.Match object; span=(76, 77), match='}'>
>>> seeker = re.compile("[a-h][g-m]")
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(5, 7), match='fg'>
<re.Match object; span=(7, 9), match='hi'>
>>> seeker = re.compile("a")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(0, 1), match='a'>
>>> t = "catamaran"
>>> seeker = re.compile("a[a-z]")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(0, 2), match='ab'>
>>> for k in seeker.finditer(t):
...     print(k)
... 
<re.Match object; span=(1, 3), match='at'>
<re.Match object; span=(3, 5), match='am'>
<re.Match object; span=(5, 7), match='ar'>
<re.Match object; span=(7, 9), match='an'>
>>> seeker = re.compile("a[a-z][a-z]")
>>> for k in seeker.finditer(t):
...     print(k)
... 
<re.Match object; span=(1, 4), match='ata'>
<re.Match object; span=(5, 8), match='ara'>
>>> t
'catamaran'
>>> seeker = re.compile("a.a")
>>> for k in seeker.finditer(t):
...     print(k)
... 
<re.Match object; span=(1, 4), match='ata'>
<re.Match object; span=(5, 8), match='ara'>
>>> seeker = re.compile("\d\d\d")
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(52, 55), match='012'>
<re.Match object; span=(55, 58), match='345'>
<re.Match object; span=(58, 61), match='678'>
>>> seeker = re.compile("\D")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(0, 1), match='a'>
<re.Match object; span=(1, 2), match='b'>
<re.Match object; span=(2, 3), match='c'>
<re.Match object; span=(3, 4), match='d'>
<re.Match object; span=(4, 5), match='e'>
<re.Match object; span=(5, 6), match='f'>
<re.Match object; span=(6, 7), match='g'>
<re.Match object; span=(7, 8), match='h'>
<re.Match object; span=(8, 9), match='i'>
<re.Match object; span=(9, 10), match='j'>
<re.Match object; span=(10, 11), match='k'>
<re.Match object; span=(11, 12), match='l'>
<re.Match object; span=(12, 13), match='m'>
<re.Match object; span=(13, 14), match='n'>
<re.Match object; span=(14, 15), match='o'>
<re.Match object; span=(15, 16), match='p'>
<re.Match object; span=(16, 17), match='q'>
<re.Match object; span=(17, 18), match='r'>
<re.Match object; span=(18, 19), match='s'>
<re.Match object; span=(19, 20), match='t'>
<re.Match object; span=(20, 21), match='u'>
<re.Match object; span=(21, 22), match='v'>
<re.Match object; span=(22, 23), match='w'>
<re.Match object; span=(23, 24), match='x'>
<re.Match object; span=(24, 25), match='y'>
<re.Match object; span=(25, 26), match='z'>
<re.Match object; span=(26, 27), match='A'>
<re.Match object; span=(27, 28), match='B'>
<re.Match object; span=(28, 29), match='C'>
<re.Match object; span=(29, 30), match='D'>
<re.Match object; span=(30, 31), match='E'>
<re.Match object; span=(31, 32), match='F'>
<re.Match object; span=(32, 33), match='G'>
<re.Match object; span=(33, 34), match='H'>
<re.Match object; span=(34, 35), match='I'>
<re.Match object; span=(35, 36), match='J'>
<re.Match object; span=(36, 37), match='K'>
<re.Match object; span=(37, 38), match='L'>
<re.Match object; span=(38, 39), match='M'>
<re.Match object; span=(39, 40), match='N'>
<re.Match object; span=(40, 41), match='O'>
<re.Match object; span=(41, 42), match='P'>
<re.Match object; span=(42, 43), match='Q'>
<re.Match object; span=(43, 44), match='R'>
<re.Match object; span=(44, 45), match='S'>
<re.Match object; span=(45, 46), match='T'>
<re.Match object; span=(46, 47), match='U'>
<re.Match object; span=(47, 48), match='V'>
<re.Match object; span=(48, 49), match='W'>
<re.Match object; span=(49, 50), match='X'>
<re.Match object; span=(50, 51), match='Y'>
<re.Match object; span=(51, 52), match='Z'>
<re.Match object; span=(63, 64), match='!'>
<re.Match object; span=(64, 65), match='@'>
<re.Match object; span=(65, 66), match='#'>
<re.Match object; span=(66, 67), match='$'>
<re.Match object; span=(67, 68), match='%'>
<re.Match object; span=(68, 69), match='^'>
<re.Match object; span=(69, 70), match='&'>
<re.Match object; span=(70, 71), match='*'>
<re.Match object; span=(71, 72), match='('>
<re.Match object; span=(72, 73), match=')'>
<re.Match object; span=(73, 74), match='_'>
<re.Match object; span=(74, 75), match='+'>
<re.Match object; span=(75, 76), match='{'>
<re.Match object; span=(76, 77), match='}'>
>>> 
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> u = "Now is the time to dine."
>>> seeker = re.compile("\s")
>>> for k in seeker.finditer(u):
...     print(k)
... 
<re.Match object; span=(3, 4), match=' '>
<re.Match object; span=(6, 7), match=' '>
<re.Match object; span=(10, 11), match=' '>
<re.Match object; span=(15, 16), match=' '>
<re.Match object; span=(18, 19), match=' '>
>>> u = re.compile("\s[a-zA-Z]")
>>> for k in seeker.finditer(u):
...     print(k)
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: expected string or bytes-like object
>>> u = "Now is the time to dine."
>>> seeker = re.compile("\s[a-zA-Z]")
>>> for k in seeker.finditer(u):
...     print(k)
... 
<re.Match object; span=(3, 5), match=' i'>
<re.Match object; span=(6, 8), match=' t'>
<re.Match object; span=(10, 12), match=' t'>
<re.Match object; span=(15, 17), match=' t'>
<re.Match object; span=(18, 20), match=' d'>
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> seeker = re.compile("\w")
>>> for k in seeker.finditer(s):
...     print(k)
... 
<re.Match object; span=(0, 1), match='a'>
<re.Match object; span=(1, 2), match='b'>
<re.Match object; span=(2, 3), match='c'>
<re.Match object; span=(3, 4), match='d'>
<re.Match object; span=(4, 5), match='e'>
<re.Match object; span=(5, 6), match='f'>
<re.Match object; span=(6, 7), match='g'>
<re.Match object; span=(7, 8), match='h'>
<re.Match object; span=(8, 9), match='i'>
<re.Match object; span=(9, 10), match='j'>
<re.Match object; span=(10, 11), match='k'>
<re.Match object; span=(11, 12), match='l'>
<re.Match object; span=(12, 13), match='m'>
<re.Match object; span=(13, 14), match='n'>
<re.Match object; span=(14, 15), match='o'>
<re.Match object; span=(15, 16), match='p'>
<re.Match object; span=(16, 17), match='q'>
<re.Match object; span=(17, 18), match='r'>
<re.Match object; span=(18, 19), match='s'>
<re.Match object; span=(19, 20), match='t'>
<re.Match object; span=(20, 21), match='u'>
<re.Match object; span=(21, 22), match='v'>
<re.Match object; span=(22, 23), match='w'>
<re.Match object; span=(23, 24), match='x'>
<re.Match object; span=(24, 25), match='y'>
<re.Match object; span=(25, 26), match='z'>
<re.Match object; span=(26, 27), match='A'>
<re.Match object; span=(27, 28), match='B'>
<re.Match object; span=(28, 29), match='C'>
<re.Match object; span=(29, 30), match='D'>
<re.Match object; span=(30, 31), match='E'>
<re.Match object; span=(31, 32), match='F'>
<re.Match object; span=(32, 33), match='G'>
<re.Match object; span=(33, 34), match='H'>
<re.Match object; span=(34, 35), match='I'>
<re.Match object; span=(35, 36), match='J'>
<re.Match object; span=(36, 37), match='K'>
<re.Match object; span=(37, 38), match='L'>
<re.Match object; span=(38, 39), match='M'>
<re.Match object; span=(39, 40), match='N'>
<re.Match object; span=(40, 41), match='O'>
<re.Match object; span=(41, 42), match='P'>
<re.Match object; span=(42, 43), match='Q'>
<re.Match object; span=(43, 44), match='R'>
<re.Match object; span=(44, 45), match='S'>
<re.Match object; span=(45, 46), match='T'>
<re.Match object; span=(46, 47), match='U'>
<re.Match object; span=(47, 48), match='V'>
<re.Match object; span=(48, 49), match='W'>
<re.Match object; span=(49, 50), match='X'>
<re.Match object; span=(50, 51), match='Y'>
<re.Match object; span=(51, 52), match='Z'>
<re.Match object; span=(52, 53), match='0'>
<re.Match object; span=(53, 54), match='1'>
<re.Match object; span=(54, 55), match='2'>
<re.Match object; span=(55, 56), match='3'>
<re.Match object; span=(56, 57), match='4'>
<re.Match object; span=(57, 58), match='5'>
<re.Match object; span=(58, 59), match='6'>
<re.Match object; span=(59, 60), match='7'>
<re.Match object; span=(60, 61), match='8'>
<re.Match object; span=(61, 62), match='9'>
<re.Match object; span=(62, 63), match='0'>
<re.Match object; span=(73, 74), match='_'>
>>> s
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890!@#$%^&*()_+{}'
>>> t
'catamaran'
>>> u
'Now is the time to dine.'
>>> seeker = re.compile("\b")
>>> for k in seeker.finditer(s):
...     print(k)
... 
>>> for k in seeker.finditer(u):
...     print(k)
... 
>>> u
'Now is the time to dine.'
>>> seeker = re.compile("\B")
>>> for k in seeker.finditer(u):
...     print(k)
... 
<re.Match object; span=(1, 1), match=''>
<re.Match object; span=(2, 2), match=''>
<re.Match object; span=(5, 5), match=''>
<re.Match object; span=(8, 8), match=''>
<re.Match object; span=(9, 9), match=''>
<re.Match object; span=(12, 12), match=''>
<re.Match object; span=(13, 13), match=''>
<re.Match object; span=(14, 14), match=''>
<re.Match object; span=(17, 17), match=''>
<re.Match object; span=(20, 20), match=''>
<re.Match object; span=(21, 21), match=''>
<re.Match object; span=(22, 22), match=''>
<re.Match object; span=(24, 24), match=''>
>>> u
'Now is the time to dine.'
>>> v = "Call  this number 800-443-1234 and you will 
  File "<stdin>", line 1
    v = "Call  this number 800-443-1234 and you will 
                                                    ^
SyntaxError: EOL while scanning string literal
>>> v = "Call  this number 800-443-1234 and you will then be referred to customer service at 900-334-2213 where they will ask for your creedit card number"
>>> 
>>> v
'Call  this number 800-443-1234 and you will then be referred to customer service at 900-334-2213 where they will ask for your creedit card number'
>>> seeker = re.compile("[2-9][0-9][0-9]-\d\d\d-\d\d\d\d")
>>> for k in seeker.finditer(v):
...     print(k.group())
... 
800-443-1234
900-334-2213
>>> v = "Call  this number 800-443-1234 and you will then be referred to customer service at 900.334.2213 where they will ask for your creedit card number"
>>> seeker = re.compile("[2-9]\d\d[-.]\d\d\d[-.]\d\d\d\d")

  File "<stdin>", line 1
    seeker = re.compile("[2-9]\d\d[-.]\d\d\d[-.]\d\d\d\d")

                                                          ^
SyntaxError: invalid character in identifier
>>> seeker = re.compile("[2-9]\d\d[-.]\d\d\d[-.]\d\d\d\d")

  File "<stdin>", line 1
    seeker = re.compile("[2-9]\d\d[-.]\d\d\d[-.]\d\d\d\d")

                                                          ^
SyntaxError: invalid character in identifier
>>> seeker = re.compile("[2-9]\d\d[-.]\d\d\d[-.]\d\d\d\d")
>>> for k in seeker.finditer(v):
...     print(k.group())
... 
800-443-1234
900.334.2213
>>> seeker = re.compile("[2-9]\d\d[\-.]\d\d\d[\-.]\d\d\d\d")
>>> 
>>> for k in seeker.finditer(v):
...     print(k.group())
... 
800-443-1234
900.334.2213
>>> >