7.5 String formatting using dictionaries

Mapping keys

• Sometimes a string contains many conversion specifiers. Such strings can be hard to read and understand.
• Furthermore, the programmer must be careful with the ordering of the tuple values, lest items are mistakenly swapped.
• A dictionary may be used instead
• If a dictionary is used, then all conversion specifiers must include a mapping key component.
  • A mapping key is specified by indicating the key of the relevant value in the dictionary within parentheses.