On Sun, 26 Sep 2010 04:15:03 am Roelof Wobben wrote: > Hello, > > I have this code: > > class zoeken() :
It is traditional to name classes with an initial capital letter, so Zoeken would be better. > pass What is the point of the "pass" statement there? That does nothing. Why did you put that there? > def __len__(self): > return 0 > def __str__(self): > return test2 What is test2? It doesn't exist. > def find(self, strng, ch, start, stop): Count the arguments: 5, including self. Remember that number. This is important later on. > index = start > while index < len(strng) and index < stop: > if strng[index] == ch: > return index > index += 1 > return -1 Watch the indentation. The "return -1" is *inside* the loop. > test = zoeken() > test.woord = "tamara" > test2 = zoeken.find(test, "a", 1,5) > print test(test2) > > But now I get this message : > > Traceback (most recent call last): > File "C:\Users\wobben\workspace\oefeningen\src\test.py", line 20, > in <module> test2 = zoeken.find(test, "a", 1,5) > TypeError: find() takes exactly 5 arguments (4 given) Right. READ THE ERROR, don't just immediately cry for help. Being a programmer means you must have ATTENTION TO DETAIL -- the error tells you *exactly* what the problem is: the find() method takes five arguments, *including* self. You have only given four arguments: find method expects: 1: self 2: strng 3: ch 4: start 5: stop find method actually gets 1: test 2: "a" 3: 1 4: 5 5: ?????????????? > I can do zoeken.find (test2,test, "a", 1,5) but then I get this > message: > > Traceback (most recent call last): > File "C:\Users\wobben\workspace\oefeningen\src\test.py", line 20, > in <module> zoeken.find( test2, test, "a", 1,5) > NameError: name 'test2' is not defined Exactly. That's because test2 does not exist. -- Steven D'Aprano _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
