After years, I found a solution with the built-in pprint
module:
import pprint
d = {'a': 'blah', 'b': 'foo', 'c': [1,2,3]}
pprint.pprint(d) # default width=80 so this will be printed in a single line
pprint.pprint(d, width=20) # here it will be wrapped exactly as expected
Output:
{'a': 'blah',
'b': 'foo',
'c': [1, 2, 3]}