A configuration file may have values of types that don't have simple string representations. For example, a collection might be provided as a tuple or list literal; a mapping might be provided as a dict literal. We have several choices to handle these more complex values.
The choices resolve around an issue of how much Python syntax the conversion is able to tolerate. For some types (int, float, bool, complex, decimal.Decimal, fractions.Fraction), we can safely convert the string to a literal value because the object __init__() for these types handle string values without tolerating any additional Python syntax.
For other types, however, we can't simply do the string conversion. We have several choices on how to proceed:
Forbid these data types and rely on the configuration file syntax plus processing rules to assemble complex Python values from very simple parts. This is tedious but can be made to work.
Use
ast.literal_eval()as it handles many...