Question

I want to introduce a variable [i] into a string in Python.

For example look at the following script. I just want to be able to give a name to the image, for example geo[0].tif … to geo[i].tif, or if you use an accountant as I can replace a portion of the value chain to generate a counter.

data = self.cmd("r.out.gdal in=rdata out=geo.tif")
self.dataOutTIF.setValue("geo.tif")

Answer 1

data = self.cmd("r.out.gdal in=rdata out=geo{0}.tif".format(i))
self.dataOutTIF.setValue("geo{0}.tif".format(i))

str.format(*args, **kwargs)

Perform a string formatting operation. The string on which this
method is called can contain literal
text or replacement fields delimited
by braces {}. Each replacement field
contains either the numeric index of a
positional argument, or the name of a
keyword argument. Returns a copy of
the string where each replacement
field is replaced with the string
value of the corresponding argument.

>>> "The sum of 1 + 2 is {0}".format(1+2)
'The sum of 1 + 2 is 3'

See Format String Syntax for a description of the various formatting
options that can be specified in
format strings.

This method of string formatting is the new standard in Python 3.0, and
should be preferred to the %
formatting described in String
Formatting Operations in new code.

New in version 2.6.