Conditionals

NRAO Home > CASA > CASA Cookbook and User Reference Manual

B.6.1 Conditionals

The standard if block handles conditional execution or branches in Python:

   if <expression>:
      <statements>
   elif <expression>:
      <statements>
   elif <expression>:
      <statements>
   ...
   else:
      <statements>

Insert a pass statement if you want no action to be taken for a particular clause. The <expression> should reduce down to True or False.

For example,

if ( importmode == ’vla’ ):
    # Import the data from VLA Export to MS
    default(’importvla’)
    print "Use importvla to read VLA Export and make an MS"

    archivefiles = datafile
    vis = msfile
    bandname = exportband
    autocorr = False
    antnamescheme = ’new’
    project = exportproject

    importvla()
elif ( importmode == ’fits’ ):
    # Import the data from VLA Export to MS
    default(’importuvfits’)
    print "Use importuvfits to read UVFITS and make an MS"

    fitsfile = datafile
    vis = msfile
    async = False

    importuvfits()
else:
    # Copy from msfile
    print "Copying "+datafile+" to "+msfile
    os.system(’cp -r ’+datafile+’ ’+msfile)
    vis = msfile

chooses branches based on the value of the importmode Python variable (set previously in script).

[next] [prev] [prev-tail] [front] [up]

More information about CASA may be found at the CASA web page

This code is available under the terms of the GNU General Public Lincense