dynamic data types

[beliavsky at aol.com]

rbt wrote:

>I've always thought of it like this... in C, we have to do something
>like this when declaring a variable:

>int x = 0;

>We had to specifically tell the language compiler that x is an
integer.
>In Python, all we have to do is:

>x = 0

>The interpretor knows that x is an integer. We can also change the
type
>like this:

>str(x)
>float(x)
>long(x)

Just to clarify, str(x) does not change x, but

x = str(x)

does. Probably rbt knows this. I wonder how often this feature should
be employed. In my Python programs, most variables keep the same type
throughout. This makes a code easier for me to understand, and this
constraint should facilitate translation of the code to a statically
typed language (perhaps even a variant of Python) in the future, if
necessary.

The ability to grow a list with "append" is a very convenient feature
of Python. The C++ vector is similar but stores elements of the same
type, whereas a Python list or tuple can store elements of different
types.