Find a substring withing a string...

Maurix maurix78_remove_this_ at wanadoo.es
Sat Jun 21 16:35:29 CEST 2003


You don't need the find() function, you need the dir() (and help() in 
the last versions) function and play with the interactive interpreter, 
try this:

 >python #(2.1 is the older that i have, i don't have 1.5 sorry)
 >>> dir()
 >>> dir(__builtins__)
['ArithmeticError', 'AssertionError', 'AttributeError', 
'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 
'Exception', 'FloatingPointError', 'IOError', 'ImportError', 
'IndentationError', 'IndexError', 'KeyError', 'KeyboardInterrupt', 
'LookupError', 'MemoryError', 'NameError', 'None', 'NotImplemented', 
'NotImplementedError', 'OSError', 'OverflowError', 'RuntimeError', 
'RuntimeWarning', 'StandardError', 'SyntaxError', 'SyntaxWarning', 
'SystemError', 'SystemExit', 'TabError', 'TypeError', 
'UnboundLocalError', 'UnicodeError', 'UserWarning', 'ValueError', 
'Warning', 'ZeroDivisionError', '__debug__', '__doc__', '__import__', 
'__name__', 'abs', 'apply', 'buffer', 'callable', 'chr', 'cmp', 
'coerce', 'compile', 'complex', 'copyright', 'credits', 'delattr', 
'dir', 'divmod', 'eval', 'execfile', 'exit', 'filter', 'float', 
'getattr', 'globals', 'hasattr', 'hash', 'hex', 'id', 'input', 'int', 
'intern', 'isinstance', 'issubclass', 'len', 'license', 'list', 
'locals', 'long', 'map', 'max', 'min', 'oct', 'open', 'ord', 'pow', 
'quit', 'range', 'raw_input', 'reduce', 'reload', 'repr', 'round', 
'setattr', 'slice', 'str', 'tuple', 'type', 'unichr', 'unicode', 'vars', 
'xrange', 'zip']
# nothing good here... let's try a good module...
 >>> import String
#... it don't work... ummm it may be...
 >>> import string
 >>> dir(string)
['_StringType', '__builtins__', '__doc__', '__file__', '__name__', 
'_float', '_idmap', '_idmapL', '_int', '_long', 'atof', 'atof_error', 
'atoi', 'atoi_error', 'atol', 'atol_error', 'capitalize', 'capwords', 
'center', 'count', 'digits', 'expandtabs', 'find', 'hexdigits', 'index', 
'index_error', 'join', 'joinfields', 'letters', 'ljust', 'lower', 
'lowercase', 'lstrip', 'maketrans', 'octdigits', 'printable', 
'punctuation', 'replace', 'rfind', 'rindex', 'rjust', 'rstrip', 'split', 
'splitfields', 'strip', 'swapcase', 'translate', 'upper', 'uppercase', 
'whitespace', 'zfill']
# Umm there is a "find" function let's tray it
 >>> find
 >>> string.find("a","a b c")
-1
#Umm... no, maybe is...
 >>> string.find("a b c","a")
0
 >>> string.find("a b c","b")
2
# Yes! exactly what i need!!
# Here with 2.1 i can make... (i don't know in 1.5)
 >>> print string.find.__doc__
find(s, sub [,start [,end]]) -> in

     Return the lowest index in s where substring sub is found,
     such that sub is contained within s[start,end].  Optional
     arguments start and end are interpreted as in slice notation.

     Return -1 on failure.

# in 2.2 you will make:
 >>> help(string.find)

and surely in new versions you can use the string object
and search in the object members:
 >>> dir("")
 >>> help("".find)


This is the advantage of use an interpreter, make this with c if you can!
The only problem that i have with this is that i find too interesting
things and i don't make my job! ;-)

And maybe you can jump to www.python.org upgrade to python2.2 and reed
the tutorial http://www.python.org/doc/current/tut/tut.html


FooBar wrote:
> 	OK I will be the first to admit that I am VERY new to Pythin and 
> know little of the syntax of this language.  I want to perform the 
> simple task of testing to see if a substring exists within string.  I 
> think the syntax is find(sting,substring) and the return is -1 if the 
> substirng is not found otherwise the start position of the substring in 
> the string.  is this correct?
> 
> 	Moreover is this code totally screwed?
> 
> 
> takeaction = find(stringvar,'LITERALSUB')
> if takeaction != -1:
>     action_to_take_if_found
> else:
>     action_tp_take_if_not_found
> 
> 
> 	Any help with this is appreciated as I am a total DFU when it 
> comes to this for now anyway...
> 
> 
> Thanks,
> DB
> 
> 
> 
> 





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