can reference the same value multiple times'{name{job{name}format(name='bob'job='dev''bob dev bob'%(name) %(job) %(name)sdict(name='bob'job='dev''bob dev bobespecially in common practicethoughthe expression seems just as simpleor simplerd dict(name='bob'job='dev''{ [name]{ [job]{ [name]}format( 'bob dev bob'{name{job{name}format(** 'bob dev bob'%(name) %(job) %(name)sd 'bob dev bobmethodkey references methoddict-to-args expressionkey references to be fairthe method has even more specialized substitution syntaxand other comparisons might favor either scheme in small ways but given the overlap and extra complexityone could argue that the format method' utility seems either washor features in search of use cases at the leastthe added conceptual burden on python programmers who may now need to know both tools doesn' seem clearly justified explicit value referencesnow optional and unlikely to be used one use case where the format method is at least debatably clearer is when there are many values to be substituted into the format string the lister py classes example we'll meet in for examplesubstitutes six items into single stringand in this case the method' {iposition labels seem marginally easier to read than the expression' % '\ % \nexpression '\ { }\nformatmethod on the other handusing dictionary keys in expressions can mitigate much of this difference this is also something of worst-case scenario for formatting complexityand not very common in practicemore typical use cases seem more of tossup furtheras of python and numbering substitution targets becomes optional when relative to positionpotentially subverting this purported benefit altogether'the { side { { }format('bright''of''life''the bright side of lifepython 'the {side {{}format('bright''of''life''the bright side of lifepython + 'the % side % % ('bright''of''life''the bright side of lifeall pythons given its concisenessthe second of these is likely to be preferred to the firstbut seems to negate part of the method' advantage compare the effect on floating-point for string fundamentals