Get list in dictionary with string interpolation

Question

I'm trying to get a value from a dictionary with string interpolation.

The dictionary has some digits, and a list of digits:

d = { "year" : 2010, \
"scenario" : 2, \
"region" : 5, \
"break_points" : [1,2,3,4,5] }

Is it possible to reference the list in a string interpolation, or do I need to identify unique keys for each?

Here's what I've tried:

str = "Year = %(year)d, \
Scenario = %(scenario)d, \
Region = %(region)d, \
Break One = %(break_points.0)d..." % d

I've also tried %(break_points[0])d, and %(break_points{'0'})d

Is this possible to do, or do I need to give them keys and save them as integers in the dictionary?

Answer 1

This is possible with new-style formatting:

print "{0[break_points][0]:d}".format(d)

or

print "{break_points[0]:d}".format(**d)

 

str.format documentation

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.

Format string syntax

The field_name itself begins with an arg_name that is either a number or a keyword. If it’s a number, it refers to a positional argument, and if it’s a keyword, it refers to a named keyword argument.

...

The arg_name can be followed by any number of index or attribute expressions. An expression of the form '.name' selects the named attribute using getattr(), while an expression of the form '[index]' does an index lookup using __getitem__().