En Mon, 23 Jul 2007 15:45:42 -0300, Robert Dailey <[EMAIL PROTECTED]> escribió:
> import csv > > def pass1( reader ): > print reader.next() > print reader.next() > > def pass2( reader ): > print reader.next() > print reader.next() > > reader = csv.reader( open( "C:/IT/Method/SpaceImpact/code/tools/ > ProfileViewer/performance_profile.csv", "rb" ) ) > > pass1( reader ) > pass2( reader ) [expecting the two calls to print the same two lines] > My understanding is that objects are passed by reference, meaning > there is no hard copy of the data, however the copies passed to > functions do not affect the version passed in. In other words, when I > call "next" on the reference passed into each function, it should not > affect the variable that was originally passed in. Both functions receive the *same* reader object, not a copy. Calling next() affects the reader internal state, it doesn't matter where you call it from. You should read this threads from last week: http://groups.google.com/group/comp.lang.python/browse_thread/thread/45732106f147ac07/ http://groups.google.com/group/comp.lang.python/browse_thread/thread/56e7d62bf66a435c/ > I'm attempting to use recursion to build a TreeCtrl in wxPython using > this data, and I can't get it to work properly if the variable outside > of the function call ends up having its state (e.g., its "next" > pointer) modified by passing it into other functions. > > Any tips on getting this to work? I'm a native C++ programmer still > learning Python, so I apologize for any confusion. Thanks. The simplest way -if the file is not so huge- is to read the whole file and keep the results in a list: lines = list(reader) There are other alternatives using the itertools module but aren't easy to grasp for a beginner. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
