issue_comments: 1154396400

Fixing that key thing (to ignore any key that is None) revealed a new bug:

``` File ~/Dropbox/Development/sqlite-utils/sqlite_utils/utils.py:376, in hash_record(record, keys) 373 if keys is not None: 374 to_hash = {key: record[key] for key in keys} 375 return hashlib.sha1( --> 376 json.dumps(to_hash, separators=(",", ":"), sort_keys=True, default=repr).encode( 377 "utf8" 378 ) 379 ).hexdigest()

File ~/.pyenv/versions/3.8.2/lib/python3.8/json/init.py:234, in dumps(obj, skipkeys, ensure_ascii, check_circular, allow_nan, cls, indent, separators, default, sort_keys, kw) 232 if cls is None: 233 cls = JSONEncoder --> 234 return cls( 235 skipkeys=skipkeys, ensure_ascii=ensure_ascii, 236 check_circular=check_circular, allow_nan=allow_nan, indent=indent, 237 separators=separators, default=default, sort_keys=sort_keys, 238 kw).encode(obj)

File ~/.pyenv/versions/3.8.2/lib/python3.8/json/encoder.py:199, in JSONEncoder.encode(self, o) 195 return encode_basestring(o) 196 # This doesn't pass the iterator directly to ''.join() because the 197 # exceptions aren't as detailed. The list call should be roughly 198 # equivalent to the PySequence_Fast that ''.join() would do. --> 199 chunks = self.iterencode(o, _one_shot=True) 200 if not isinstance(chunks, (list, tuple)): 201 chunks = list(chunks)

File ~/.pyenv/versions/3.8.2/lib/python3.8/json/encoder.py:257, in JSONEncoder.iterencode(self, o, _one_shot) 252 else: 253 _iterencode = _make_iterencode( 254 markers, self.default, _encoder, self.indent, floatstr, 255 self.key_separator, self.item_separator, self.sort_keys, 256 self.skipkeys, _one_shot) --> 257 return _iterencode(o, 0)

TypeError: '<' not supported between instances of 'NoneType' and 'str' ```