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| -rw-r--r-- | Doc/faq/programming.rst | 40 |
1 files changed, 8 insertions, 32 deletions
diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst index 1e94c34..fe4e39d 100644 --- a/Doc/faq/programming.rst +++ b/Doc/faq/programming.rst @@ -901,11 +901,11 @@ There are various techniques. Is there an equivalent to Perl's chomp() for removing trailing newlines from strings? ------------------------------------------------------------------------------------- -Starting with Python 2.2, you can use ``S.rstrip("\r\n")`` to remove all -occurrences of any line terminator from the end of the string ``S`` without -removing other trailing whitespace. If the string ``S`` represents more than -one line, with several empty lines at the end, the line terminators for all the -blank lines will be removed:: +You can use ``S.rstrip("\r\n")`` to remove all occurrences of any line +terminator from the end of the string ``S`` without removing other trailing +whitespace. If the string ``S`` represents more than one line, with several +empty lines at the end, the line terminators for all the blank lines will +be removed:: >>> lines = ("line 1 \r\n" ... "\r\n" @@ -916,15 +916,6 @@ blank lines will be removed:: Since this is typically only desired when reading text one line at a time, using ``S.rstrip()`` this way works well. -For older versions of Python, there are two partial substitutes: - -- If you want to remove all trailing whitespace, use the ``rstrip()`` method of - string objects. This removes all trailing whitespace, not just a single - newline. - -- Otherwise, if there is only one line in the string ``S``, use - ``S.splitlines()[0]``. - Is there a scanf() or sscanf() equivalent? ------------------------------------------ @@ -1042,15 +1033,8 @@ list, deleting duplicates as you go:: else: last = mylist[i] -If all elements of the list may be used as dictionary keys (i.e. they are all -hashable) this is often faster :: - - d = {} - for x in mylist: - d[x] = 1 - mylist = list(d.keys()) - -In Python 2.5 and later, the following is possible instead:: +If all elements of the list may be used as set keys (i.e. they are all +:term:`hashable`) this is often faster :: mylist = list(set(mylist)) @@ -1420,15 +1404,7 @@ not:: C.count = 314 -Static methods are possible since Python 2.2:: - - class C: - def static(arg1, arg2, arg3): - # No 'self' parameter! - ... - static = staticmethod(static) - -With Python 2.4's decorators, this can also be written as :: +Static methods are possible:: class C: @staticmethod |