import traceback
import json

def cvt(s):
    if isinstance(s, str):
        return s
    try:
        return json.dumps(s, indent = 4)
    except TypeError:
        return str(s)

def dump(*vals):
    # http://docs.python.org/library/traceback.html
    stack= traceback.extract_stack()
    vars= stack[-2][3]

    # strip away the call to dump()
    vars= '('.join(vars.split('(')[1:])
    vars= ')'.join(vars.split(')')[:-1])

    vals= [cvt(v) for v in vals]
    has_newline = sum(1 for v in vals if '\n' in v)
    if has_newline:
        print('%s:' % vars)
        print(', '.join(vals))
    else:
        print('%s:' % vars, ', '.join(vals))