data = {'unit': 'celsius', 'value':20}
"The temperature in %(unit)s is %(value)f degrees" % data
data = {'unit': 'celsius', 'value':20}
"The temperature in {unit}s is {value}f degrees".format(**data)
data = {'unit': 'celsius', 'value':20}
"The temperature in %(unit)s is %(value)f degrees" % data
data = {'unit': 'celsius', 'value':20}
"The temperature in {unit}s is {value}f degrees".format(**data)