>>> Arrays of chars are dangerous. If you insist, use Python lists of >>> Python "chars" (strings of length 1). >> Why are they more dangerous than a self-written mutable string? > > I didn't say that. I meant that arrays in the C++ sense are dangerous.
So what? Python's arrays are backed by arrays of the type they have, whereas lists are represented by arrays of python objects. Both arrays of some kind. Both hide this behind a convenient API whcih don't put any responsibility on the programmer's shoulder. Now I ask again: where is that dangerous, or more dangerous than writing your own mutable string? > C++ offers pass by value options. That makes it so you never need to > worry about messing up data that doesn't belong to you unless you > explicitly pass by reference. Python doesn't do this for you. Thus, a > mutable string class in Python requires a great deal more care since > you need to make copies of every string in every function in order to > prevent changes in one object's string from affecting another. While you are technically correct, it strikes me odd that someone uses mutable strings in a scenario where he also wants copy-semantics for pass-by-value. That is plain stupid: create O(n) complexity to achieve what immutable strings buy you for O(1). So: Yes, mutable strings are dangerous. Use them only when their benefits outweigh their risks. But you argumentation regarding C++ is odd to say the least. Especially since the cited call-by-value semantics doesn't come for free - designing and implementing assignment operators and copy-constructors is a daunting task in itself. And if you WANT to use mutable strings with a call-by-value semantic in python, a simple decorator that scans arguments for mutable strings could help you there. Diez -- http://mail.python.org/mailman/listinfo/python-list
