d = deque('ghi') # make a new deque with three items for elem in d: # iterate over the deque's elements ! print elem.upper() ! ! G H I d.append('j') # add a new entry to the right side d.appendleft('f') # add a new entry to the left side d # show the representation of the deque deque(['f', 'g', 'h', 'i', 'j']) d.pop() # return and remove the rightmost item 'j' --- 91,104 ---- d = deque('ghi') # make a new deque with three items for elem in d: # iterate over the deque's elements ! ... print elem.upper() G H I
d.append('j') # add a new entry to the right side d.appendleft('f') # add a new entry to the left side d # show the representation of the deque deque(['f', 'g', 'h', 'i', 'j'])
Update of /cvsroot/python/python/dist/src/Doc/lib In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv24444/Doc/lib Modified Files: libcollections.tex Log Message: Improvements to collections.deque(): * Add doctests for the examples in the library reference. * Add two methods, left() and right(), modeled after deques in C++ STL. * Apply the new method to asynchat.py. * Add comparison operators to make deques more substitutable for lists. * Replace the LookupErrors with IndexErrors to more closely match lists. Index: libcollections.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/libcollections.tex,v retrieving revision 1.4 retrieving revision 1.5 diff -C2 -d -r1.4 -r1.5 *** libcollections.tex 7 Feb 2004 21:12:59 -0000 1.4 --- libcollections.tex 29 Feb 2004 02:15:55 -0000 1.5 *************** *** 55,66 **** \end{methoddesc} \begin{methoddesc}{pop}{} Remove and return an element from the right side of the deque. ! If no elements are present, raises a \exception{LookupError}. \end{methoddesc} \begin{methoddesc}{popleft}{} Remove and return an element from the left side of the deque. ! If no elements are present, raises a \exception{LookupError}. \end{methoddesc} --- 55,76 ---- \end{methoddesc} + \begin{methoddesc}{left}{} + Return leftmost element from the deque. + If no elements are present, raises a \exception{IndexError}. + \end{methoddesc} + \begin{methoddesc}{pop}{} Remove and return an element from the right side of the deque. ! If no elements are present, raises a \exception{IndexError}. \end{methoddesc} \begin{methoddesc}{popleft}{} Remove and return an element from the left side of the deque. ! If no elements are present, raises a \exception{IndexError}. ! \end{methoddesc} ! ! \begin{methoddesc}{right}{} ! Return the rightmost element from the deque. ! If no elements are present, raises a \exception{IndexError}. \end{methoddesc} *************** *** 81,94 **** + +
d.pop() # return and remove the rightmost item 'j'
list(d) # list the contents of the deque ['g', 'h', 'i']
*** 97,100 **** --- 107,115 ---- + + >>> d.left() # peek at leftmost item + 'g' + >>> d.right() # peek at rightmost item + 'i'
list(reversed(d)) # list the contents of a deque in reverse ['i', 'h', 'g']
d deque(['g', 'h', 'i', 'j', 'k', 'l']) deque(reversed(d)) # make a new deque in reverse order deque(['l', 'k', 'j', 'i', 'h', 'g']) d.clear() # empty the deque d.pop() # cannot pop from an empty deque
d.extendleft('abc') # extendleft() reverses the input order --- 125,137 ---- d deque(['g', 'h', 'i', 'j', 'k', 'l'])
*** 110,122 **** - Traceback (most recent call last): File "<pyshell#6>", line 1, in -toplevel- d.pop() ! LookupError: pop from an empty deque +
deque(reversed(d)) # make a new deque in reverse order deque(['l', 'k', 'j', 'i', 'h', 'g']) d.clear() # empty the deque d.pop() # cannot pop from an empty deque Traceback (most recent call last): File "<pyshell#6>", line 1, in -toplevel- d.pop() ! IndexError: pop from an empty deque
d.extendleft('abc') # extendleft() reverses the input order