How to check a string for specific characters

Question

How can I check if a string has several specific characters in it using Python 2   For example  given the following string      The criminals stole  1 000 000 in jewels    How do I detect if it has dollar signs        commas        and numbers

User · Answer

s input  Enter any character       if s isalnum          print  Alpha Numeric Character         if s isalpha              print  Alphabet character             if s islower                print  Lower case alphabet character             else              print  Upper case alphabet character         else          print  it is a digit      elif s isspace           print  It is space character        else       print  Non Space Special Character

User · Answer

Assuming your string is s       in s          found     not in s      not found    original answer given  but less Pythonic than the above    s find       -1   not found s find       -1   found   And so on for other characters       or  pattern   re compile r  d      if pattern findall s       print  Found   else     print  Not found         or  chars   set  0123456789     if any  c in chars  for c in s       print  Found   else      print  Not Found      Edit  added the     in s answers

User · Answer

user Jochen Ritzel said this in a comment to an answer to this question from user dappawit  It should work     1  in var  and   2  in var  and   3  in var         1    2   etc  should be replaced with the characters you are looking for   See this page in the Python 2 7 documentation for some information on strings  including about using the in operator for substring tests   Update  This does the same job as my above suggestion with less repetition     When looking for single characters  this checks for any of the characters         since strings are collections of characters any i in   lt string gt   for i in  123     any i in  a  for i in  123   - gt  False   any i in  b3  for i in  123   - gt  True    And when looking for subsrings any i in   lt string gt   for i in   11   22   33      any i in  hello  for i in   18   36   613    - gt  False   any i in  613 mitzvahs  for i in   18   36   613    - gt True

User · Answer

Quick comparison of timings in response to the post by Abbafei   import timeit  def func1        phrase    Lucky Dog      return any i in  LD  for i in phrase   def func2        phrase    Lucky Dog      if   L  in phrase  or   D  in phrase           return True     else          return False  if   name         main          func1 time   timeit timeit func1  number 100000      func2 time   timeit timeit func2  number 100000      print  Func1 Time   0  nFunc2 Time   1   format func1 time  func2 time     Output   Func1 Time  0 0737484362111 Func2 Time  0 0125144964371   So the code is more compact with any  but faster with the conditional     EDIT   TL DR -- For long strings  if-then is still much faster than any    I decided to compare the timing for a long random string based on some of the valid points raised in the comments     Tested in Python 2 7 14  import timeit from string import ascii letters from random import choice  def create random string length 1000       random list    choice ascii letters  for x in range length       return    join random list   def function using any phrase       return any i in  LD  for i in phrase   def function using if then phrase       if   L  in phrase  or   D  in phrase           return True     else          return False  if   name         main         random string   create random string length 2000      func1 time   timeit timeit stmt  function using any random string                                   setup  from   main   import function using any  random string                                  number 200000      func2 time   timeit timeit stmt  function using if then random string                                   setup  from   main   import function using if then  random string                                  number 200000      print  Time for function using any   0  nTime for function using if-then   1   format func1 time  func2 time     Output   Time for function using any  0 1342546 Time for function using if-then  0 0201827   If-then is almost an order of magnitude faster than any

User · Answer

My simple  simple  simple approach   D Code string to test    quot The criminals stole  1 000 000 in jewels  quot  chars to check     quot   quot    quot   quot    quot 0 quot    quot 1 quot    quot 2 quot    quot 3 quot    quot 4 quot    quot 5 quot    quot 6 quot    quot 7 quot    quot 8 quot    quot 9 quot   for char in chars to check      if char in string to test          print  quot Char   quot  quot    char    quot   quot  detected  quot    Output Char  quot   quot  detected  Char  quot   quot  detected  Char  quot 0 quot  detected  Char  quot 1 quot  detected   Thanks

User · Answer

This will test if strings are made up of some combination or digits  the dollar sign  and a commas  Is that what you re looking for    import re  s1    Testing string  s2    1234 12345    regex   re compile   0-9         if   regex match s1        print  s1 matched  else     print  s1 didn t match   if   regex match s2        print  s2 matched  else     print  s2 didn t match

[python] How to check a string for specific characters?

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