[Tutor] Java style assignments in Python

[Jeff Shannon]

tpc at csua.berkeley.edu wrote:
> hi Zak, well I was more familiar with Java's strong typing that I assumed
> Python allowed assignment of a type to three variables.

Python has fairly strong typing too, but the type belongs to the 
object, *not* to the variable name that is bound to it.  It may be 
somewhat helpful to think of all Python variables as being 
references... but even that's not completely correct.

In Python, everything is an object, and that object is independent of 
any names that are bound to it, and any object can have any number of 
names.  The assignment operator, =, binds (or re-binds) a name (on the 
left-hand side) to an object (on the right-hand side).

In languages like C and Java, you can think of variables as a box that 
you put stuff in.  Type-checking ensures that the stuff is the same 
shape as the box.  In Python, variables are more like sticky-notes 
that you can stick to an object.  It's easy to move a sticky note from 
one object to another, even if that other object is of a different 
shape (type).  If you try to perform an operation with two objects, 
they will let you know if they don't fit together.  (Perl, on the 
other hand, will take a hammer and *make* them fit together! ;) )

Jeff Shannon
Technician/Programmer
Credit International