Raise From Previous Error

Sourcery refactoring id: raise-from-previous-error

Description:

Suggests raising from a previously-raised exception.

Before:

x = int(input())

try:
    print(1 / x)
except ZeroDivisionError:
    raise ValueError("Can't divide by zero")

After:

x = int(input())

try:
    print(1 / x)
except ZeroDivisionError as e:
    raise ValueError("Can't divide by zero") from e

Explanation:

Exception chaining was introduced in Python 3 PEP 3134, and is an implicit part of exception handling. This suggestion converts the implicit exception chain into an explicit one, as suggested by Pylint's raise-missing-from error.