Variables

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1.3.7.1 Variables

Python variables are set using the <parameter> = <value> syntax. Python assigns the type dynamically as you set the value, and thus you can easily give it a non-sensical value, e.g.

vis = ’ngc5921.ms’
vis = 1

The CASA parameter system will check types when you run a task or tool, or more helpfully when you set inputs using inp (see below). CASA will check and protect the assignments of the global parameters in its namespace.

Note that Python variable names are case-sensitive:

CASA <109>: Foo = ’bar’
CASA <110>: foo = ’Bar’
CASA <111>: foo
Out[111]: ’Bar’
CASA <112>: Foo
Out[112]: ’bar’

so be careful.

Also note that mis-spelling a variable assignment will not be noticed (as long as it is a valid Python variable name) by the interface. For example, if you wish to set correlation=’RR’ but instead type corellation=’RR’ you will find correlation unset and a new corellation variable set. Command completion (see §1.3.8.1) should help you avoid this.

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