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Diffstat (limited to 'Doc/tutorial/classes.rst')
| -rw-r--r-- | Doc/tutorial/classes.rst | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst index b733e1e..09cc0e1 100644 --- a/Doc/tutorial/classes.rst +++ b/Doc/tutorial/classes.rst @@ -14,7 +14,8 @@ multiple base classes, a derived class can override any methods of its base class or classes, and a method can call the method of a base class with the same name. Objects can contain an arbitrary amount of private data. -In C++ terminology, all class members (including the data members) are *public*, +In C++ terminology, normally class members (including the data members) are +*public* (except see below :ref:`tut-private`), and all member functions are *virtual*. There are no special constructors or destructors. As in Modula-3, there are no shorthands for referencing the object's members from its methods: the method function is declared with an @@ -273,7 +274,7 @@ code will print the value ``16``, without leaving a trace:: x.counter = 1 while x.counter < 10: x.counter = x.counter * 2 - print x.counter + print(x.counter) del x.counter The other kind of instance attribute reference is a *method*. A method is a @@ -308,7 +309,7 @@ object, and can be stored away and called at a later time. For example:: xf = x.f while True: - print xf() + print(xf()) will continue to print ``hello world`` until the end of time. @@ -621,11 +622,11 @@ following code will print B, C, D in that order:: try: raise c() except D: - print "D" + print("D") except C: - print "C" + print("C") except B: - print "B" + print("B") Note that if the except clauses were reversed (with ``except B`` first), it would have printed B, B, B --- the first matching except clause is triggered. @@ -644,15 +645,15 @@ By now you have probably noticed that most container objects can be looped over using a :keyword:`for` statement:: for element in [1, 2, 3]: - print element + print(element) for element in (1, 2, 3): - print element + print(element) for key in {'one':1, 'two':2}: - print key + print(key) for char in "123": - print char + print(char) for line in open("myfile.txt"): - print line + print(line) This style of access is clear, concise, and convenient. The use of iterators pervades and unifies Python. Behind the scenes, the :keyword:`for` statement @@ -699,7 +700,7 @@ returns an object with a :meth:`__next__` method. If the class defines return self.data[self.index] >>> for char in Reverse('spam'): - ... print char + ... print(char) ... m a @@ -724,7 +725,7 @@ create:: yield data[index] >>> for char in reverse('golf'): - ... print char + ... print(char) ... f l |