pyminifier2.1,2.2不支持python3.6的 f-string
>>> name = "Fred"
>>> f"He said his name is {name}."
\'He said his name is Fred.\'
>>> width = 10
>>> precision = 4
>>> value = decimal.Decimal("12.34567")
>>> f"result: {value:{width}.{precision}}" # nested fields
\'result: 12.35\'
pyminifier不会混淆{}中的变量名。