Use logging print the output of pprint
PythonLoggingPprintPython Problem Overview
I want to use pprint's output to show a complex data structure, but I would like to output it using the logging module rather than stdout.
ds = [{'hello': 'there'}]
logging.debug( pprint.pprint(ds) ) # outputs as STDOUT
Python Solutions
Solution 1 - Python
Use pprint.pformat to get a string, and then send it to your logging framework.
from pprint import pformat
ds = [{'hello': 'there'}]
logging.debug(pformat(ds))
Solution 2 - Python
The solution above didn't quite cut it for me because I'm also using a formatter to add name and levelname when logging. It looks a little untidy:
__main__ : DEBUG : ['aaaaaaaaaaaaaaaaaaaa',
'bbbbbbbbbbbbbbbbbbbb',
'cccccccccccccccccccc',
'dddddddddddddddddddd']
__main__ : DEBUG : Some other logging text
There may be a more elegant solution, but this:
for line in pprint.pformat(ds).split('\n'):
logging.debug(line)
produces something a little nicer:
__main__ : DEBUG : ['aaaaaaaaaaaaaaaaaaaa',
__main__ : DEBUG : 'bbbbbbbbbbbbbbbbbbbb',
__main__ : DEBUG : 'cccccccccccccccccccc',
__main__ : DEBUG : 'dddddddddddddddddddd']
__main__ : DEBUG : Some other logging text
Solution 3 - Python
An alternative is to use json.dumps with the indent arg. In some cases (depending on logging format, data size, etc) it might give you nicer output.
logging.error('Malformed input data!')
logging.error(pformat(foo))
ERROR:root:Malformed input data!
ERROR:root:{'a': 1, 'b': 2, 'c': 'womp rat', 'd': 'turd sandwich'}
vs.
logging.error('Malformed input data!')
logging.error(json.dumps(foo, indent=4))
ERROR:root:Malformed input data!
ERROR:root:{
"a": 1,
"b": 2,
"c": "womp rat",
"d": "turd sandwich"
}