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一本很好的python的说明书,适合对python感兴趣的人

  Return the lowest index in <var>s</var> where the substring <var>sub</var> is
  found such that <var>sub</var> is wholly contained in
  <code><var>s</var>[<var>start</var>:<var>end</var>]</code>.  Return <code>-1</code> on failure.
  Defaults for <var>start</var> and <var>end</var> and interpretation of
  negative values is the same as for slices.
</dl>

<P>
<dl><dt><b><a name='l2h-559'><tt class='function'>rfind</tt></a></b> (<var>s, sub</var><big>[</big><var>, start</var><big>[</big><var>, end</var><big>]</big><big>]</big>)
<dd>
  Like <tt class="function">find()</tt> but find the highest index.
</dl>

<P>
<dl><dt><b><a name='l2h-560'><tt class='function'>index</tt></a></b> (<var>s, sub</var><big>[</big><var>, start</var><big>[</big><var>, end</var><big>]</big><big>]</big>)
<dd>
  Like <tt class="function">find()</tt> but raise <tt class="exception">ValueError</tt> when the
  substring is not found.
</dl>

<P>
<dl><dt><b><a name='l2h-561'><tt class='function'>rindex</tt></a></b> (<var>s, sub</var><big>[</big><var>, start</var><big>[</big><var>, end</var><big>]</big><big>]</big>)
<dd>
  Like <tt class="function">rfind()</tt> but raise <tt class="exception">ValueError</tt> when the
  substring is not found.
</dl>

<P>
<dl><dt><b><a name='l2h-562'><tt class='function'>count</tt></a></b> (<var>s, sub</var><big>[</big><var>, start</var><big>[</big><var>, end</var><big>]</big><big>]</big>)
<dd>
  Return the number of (non-overlapping) occurrences of substring
  <var>sub</var> in string <code><var>s</var>[<var>start</var>:<var>end</var>]</code>.
  Defaults for <var>start</var> and <var>end</var> and interpretation of
  negative values are the same as for slices.
</dl>

<P>
<dl><dt><b><a name='l2h-563'><tt class='function'>lower</tt></a></b> (<var>s</var>)
<dd>
  Return a copy of <var>s</var>, but with upper case letters converted to
  lower case.
</dl>

<P>
<dl><dt><b><a name='l2h-564'><tt class='function'>maketrans</tt></a></b> (<var>from, to</var>)
<dd>
  Return a translation table suitable for passing to
  <tt class="function">translate()</tt> or <tt class="function">regex.compile()</tt>, that will map
  each character in <var>from</var> into the character at the same position
  in <var>to</var>; <var>from</var> and <var>to</var> must have the same length.

<P>
<b>Warning:</b> don't use strings derived from <tt class="constant">lowercase</tt>
  and <tt class="constant">uppercase</tt> as arguments; in some locales, these don't have
  the same length.  For case conversions, always use
  <tt class="function">lower()</tt> and <tt class="function">upper()</tt>.
</dl>

<P>
<dl><dt><b><a name='l2h-565'><tt class='function'>split</tt></a></b> (<var>s</var><big>[</big><var>, sep</var><big>[</big><var>, maxsplit</var><big>]</big><big>]</big>)
<dd>
  Return a list of the words of the string <var>s</var>.  If the optional
  second argument <var>sep</var> is absent or <code>None</code>, the words are
  separated by arbitrary strings of whitespace characters (space, tab, 
  newline, return, formfeed).  If the second argument <var>sep</var> is
  present and not <code>None</code>, it specifies a string to be used as the 
  word separator.  The returned list will then have one more item
  than the number of non-overlapping occurrences of the separator in
  the string.  The optional third argument <var>maxsplit</var> defaults to
  0.  If it is nonzero, at most <var>maxsplit</var> number of splits occur,
  and the remainder of the string is returned as the final element of
  the list (thus, the list will have at most <code><var>maxsplit</var>+1</code>
  elements).
</dl>

<P>
<dl><dt><b><a name='l2h-566'><tt class='function'>splitfields</tt></a></b> (<var>s</var><big>[</big><var>, sep</var><big>[</big><var>, maxsplit</var><big>]</big><big>]</big>)
<dd>
  This function behaves identically to <tt class="function">split()</tt>.  (In the
  past, <tt class="function">split()</tt> was only used with one argument, while
  <tt class="function">splitfields()</tt> was only used with two arguments.)
</dl>

<P>
<dl><dt><b><a name='l2h-567'><tt class='function'>join</tt></a></b> (<var>words</var><big>[</big><var>, sep</var><big>]</big>)
<dd>
  Concatenate a list or tuple of words with intervening occurrences of 
  <var>sep</var>.  The default value for <var>sep</var> is a single space
  character.  It is always true that
  "<tt class="samp">string.join(string.split(<var>s</var>, <var>sep</var>), <var>sep</var>)</tt>"  equals <var>s</var>.
</dl>

<P>
<dl><dt><b><a name='l2h-568'><tt class='function'>joinfields</tt></a></b> (<var>words</var><big>[</big><var>, sep</var><big>]</big>)
<dd>
  This function behaves identical to <tt class="function">join()</tt>.  (In the past, 
  <tt class="function">join()</tt> was only used with one argument, while
  <tt class="function">joinfields()</tt> was only used with two arguments.)
</dl>

<P>
<dl><dt><b><a name='l2h-569'><tt class='function'>lstrip</tt></a></b> (<var>s</var>)
<dd>
  Return a copy of <var>s</var> but without leading whitespace characters.
</dl>

<P>
<dl><dt><b><a name='l2h-570'><tt class='function'>rstrip</tt></a></b> (<var>s</var>)
<dd>
  Return a copy of <var>s</var> but without trailing whitespace
  characters.
</dl>

<P>
<dl><dt><b><a name='l2h-571'><tt class='function'>strip</tt></a></b> (<var>s</var>)
<dd>
  Return a copy of <var>s</var> without leading or trailing whitespace.
</dl>

<P>
<dl><dt><b><a name='l2h-572'><tt class='function'>swapcase</tt></a></b> (<var>s</var>)
<dd>
  Return a copy of <var>s</var>, but with lower case letters
  converted to upper case and vice versa.
</dl>

<P>
<dl><dt><b><a name='l2h-573'><tt class='function'>translate</tt></a></b> (<var>s, table</var><big>[</big><var>, deletechars</var><big>]</big>)
<dd>
  Delete all characters from <var>s</var> that are in <var>deletechars</var> (if 
  present), and then translate the characters using <var>table</var>, which 
  must be a 256-character string giving the translation for each
  character value, indexed by its ordinal.  
</dl>

<P>
<dl><dt><b><a name='l2h-574'><tt class='function'>upper</tt></a></b> (<var>s</var>)
<dd>
  Return a copy of <var>s</var>, but with lower case letters converted to
  upper case.
</dl>

<P>
<dl><dt><b><a name='l2h-575'><tt class='function'>ljust</tt></a></b> (<var>s, width</var>)
<dd>
<dt><b><tt class='function'>rjust</tt></b> (<var>s, width</var>)
<dd>
<dt><b><tt class='function'>center</tt></b> (<var>s, width</var>)
<dd>
  These functions respectively left-justify, right-justify and center
  a string in a field of given width.  They return a string that is at
  least <var>width</var> characters wide, created by padding the string
  <var>s</var> with spaces until the given width on the right, left or both
  sides.  The string is never truncated.
</dl>

<P>
<dl><dt><b><a name='l2h-576'><tt class='function'>zfill</tt></a></b> (<var>s, width</var>)
<dd>
  Pad a numeric string on the left with zero digits until the given
  width is reached.  Strings starting with a sign are handled
  correctly.
</dl>

<P>
<dl><dt><b><a name='l2h-577'><tt class='function'>replace</tt></a></b> (<var>str, old, new</var><big>[</big><var>, maxsplit</var><big>]</big>)
<dd>
  Return a copy of string <var>str</var> with all occurrences of substring
  <var>old</var> replaced by <var>new</var>.  If the optional argument
  <var>maxsplit</var> is given, the first <var>maxsplit</var> occurrences are
  replaced.
</dl>

<P>
This module is implemented in Python.  Much of its functionality has
been reimplemented in the built-in module
<tt class="module">strop</tt>.  However, you
should <i>never</i> import the latter module directly.  When
<tt class="module">string</tt> discovers that <tt class="module">strop</tt> exists, it transparently
replaces parts of itself with the implementation from <tt class="module">strop</tt>.
After initialization, there is <i>no</i> overhead in using
<tt class="module">string</tt> instead of <tt class="module">strop</tt>.

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