Why TypeError: 'str' object is not callable?

[Randall Parker]

Using Python 2.4.2 on Windows 2000 in SPE.

Getting:
TypeError: 'str' object is not callable

on this line:

TmpErrMsg1 = "State machine %s " (StateMachineName)

In Winpdb 1.0.6 the StateMachineName is of type str in the Namespace |
Local window of local variables. It even has the string value I expect
of 'ExampleAO'. That string variable was originally set in another
variable by reading a socket packet field. Then it was assigned to
StateMachineName.

I'm not using str as a variable. I searched all my source code.

So why can't I do this?

Is there a way to test what "str" is? Maybe importing the minidom
messed up what str is? This code used to work. I am trying to figure
out what caused it to cease to work.

Any ideas?