1"""The ColoredFormatter class."""
2
3import logging
4import os
5import sys
6import typing
7
8import colorlog.escape_codes
9
10__all__ = (
11 "default_log_colors",
12 "ColoredFormatter",
13 "LevelFormatter",
14 "TTYColoredFormatter",
15)
16
17# Type aliases used in function signatures.
18EscapeCodes = typing.Mapping[str, str]
19LogColors = typing.Mapping[str, str]
20SecondaryLogColors = typing.Mapping[str, LogColors]
21if sys.version_info >= (3, 8):
22 _FormatStyle = typing.Literal["%", "{", "$"]
23else:
24 _FormatStyle = str
25
26# The default colors to use for the debug levels
27default_log_colors = {
28 "DEBUG": "white",
29 "INFO": "green",
30 "WARNING": "yellow",
31 "ERROR": "red",
32 "CRITICAL": "bold_red",
33}
34
35# The default format to use for each style
36default_formats = {
37 "%": "%(log_color)s%(levelname)s:%(name)s:%(message)s",
38 "{": "{log_color}{levelname}:{name}:{message}",
39 "$": "${log_color}${levelname}:${name}:${message}",
40}
41
42
43class ColoredRecord:
44 """
45 Wraps a LogRecord, adding escape codes to the internal dict.
46
47 The internal dict is used when formatting the message (by the PercentStyle,
48 StrFormatStyle, and StringTemplateStyle classes).
49 """
50
51 def __init__(self, record: logging.LogRecord, escapes: EscapeCodes) -> None:
52 self.__dict__.update(record.__dict__)
53 self.__dict__.update(escapes)
54
55
56class ColoredFormatter(logging.Formatter):
57 """
58 A formatter that allows colors to be placed in the format string.
59
60 Intended to help in creating more readable logging output.
61 """
62
63 def __init__(
64 self,
65 fmt: typing.Optional[str] = None,
66 datefmt: typing.Optional[str] = None,
67 style: _FormatStyle = "%",
68 log_colors: typing.Optional[LogColors] = None,
69 reset: bool = True,
70 secondary_log_colors: typing.Optional[SecondaryLogColors] = None,
71 validate: bool = True,
72 stream: typing.Optional[typing.IO] = None,
73 no_color: bool = False,
74 force_color: bool = False,
75 defaults: typing.Optional[typing.Mapping[str, typing.Any]] = None,
76 ) -> None:
77 """
78 Set the format and colors the ColoredFormatter will use.
79
80 The ``fmt``, ``datefmt``, ``style``, and ``default`` args are passed on to the
81 ``logging.Formatter`` constructor.
82
83 The ``secondary_log_colors`` argument can be used to create additional
84 ``log_color`` attributes. Each key in the dictionary will set
85 ``{key}_log_color``, using the value to select from a different
86 ``log_colors`` set.
87
88 :Parameters:
89 - fmt (str): The format string to use.
90 - datefmt (str): A format string for the date.
91 - log_colors (dict):
92 A mapping of log level names to color names.
93 - reset (bool):
94 Implicitly append a color reset to all records unless False.
95 - style ('%' or '{' or '$'):
96 The format style to use.
97 - secondary_log_colors (dict):
98 Map secondary ``log_color`` attributes. (*New in version 2.6.*)
99 - validate (bool)
100 Validate the format string.
101 - stream (typing.IO)
102 The stream formatted messages will be printed to. Used to toggle colour
103 on non-TTY outputs. Optional.
104 - no_color (bool):
105 Disable color output.
106 - force_color (bool):
107 Enable color output. Takes precedence over `no_color`.
108 """
109
110 # Select a default format if `fmt` is not provided.
111 fmt = default_formats[style] if fmt is None else fmt
112
113 if sys.version_info >= (3, 10):
114 super().__init__(fmt, datefmt, style, validate, defaults=defaults)
115 elif sys.version_info >= (3, 8):
116 super().__init__(fmt, datefmt, style, validate)
117 else:
118 super().__init__(fmt, datefmt, style)
119
120 self.log_colors = log_colors if log_colors is not None else default_log_colors
121 self.secondary_log_colors = (
122 secondary_log_colors if secondary_log_colors is not None else {}
123 )
124 self.reset = reset
125 self.stream = stream
126 self.no_color = no_color
127 self.force_color = force_color
128
129 def formatMessage(self, record: logging.LogRecord) -> str:
130 """Format a message from a record object."""
131 escapes = self._escape_code_map(record.levelname)
132 wrapper = ColoredRecord(record, escapes)
133 message = super().formatMessage(wrapper) # type: ignore
134 message = self._append_reset(message, escapes)
135 return message
136
137 def _escape_code_map(self, item: str) -> EscapeCodes:
138 """
139 Build a map of keys to escape codes for use in message formatting.
140
141 If _blank_escape_codes() returns True, all values will be an empty string.
142 """
143 codes = {**colorlog.escape_codes.escape_codes}
144 codes.setdefault("log_color", self._get_escape_code(self.log_colors, item))
145 for name, colors in self.secondary_log_colors.items():
146 codes.setdefault("%s_log_color" % name, self._get_escape_code(colors, item))
147 if self._blank_escape_codes():
148 codes = {key: "" for key in codes.keys()}
149 return codes
150
151 def _blank_escape_codes(self):
152 """Return True if we should be prevented from printing escape codes."""
153 if self.force_color or "FORCE_COLOR" in os.environ:
154 return False
155
156 if self.no_color or "NO_COLOR" in os.environ:
157 return True
158
159 if self.stream is not None and not self.stream.isatty():
160 return True
161
162 return False
163
164 @staticmethod
165 def _get_escape_code(log_colors: LogColors, item: str) -> str:
166 """Extract a color sequence from a mapping, and return escape codes."""
167 return colorlog.escape_codes.parse_colors(log_colors.get(item, ""))
168
169 def _append_reset(self, message: str, escapes: EscapeCodes) -> str:
170 """Add a reset code to the end of the message, if it's not already there."""
171 reset_escape_code = escapes["reset"]
172
173 if self.reset and not message.endswith(reset_escape_code):
174 message += reset_escape_code
175
176 return message
177
178
179class LevelFormatter:
180 """An extension of ColoredFormatter that uses per-level format strings."""
181
182 def __init__(self, fmt: typing.Mapping[str, str], **kwargs: typing.Any) -> None:
183 """
184 Configure a ColoredFormatter with its own format string for each log level.
185
186 Supports fmt as a dict. All other args are passed on to the
187 ``colorlog.ColoredFormatter`` constructor.
188
189 :Parameters:
190 - fmt (dict):
191 A mapping of log levels (represented as strings, e.g. 'WARNING') to
192 format strings. (*New in version 2.7.0)
193 (All other parameters are the same as in colorlog.ColoredFormatter)
194
195 Example:
196
197 formatter = colorlog.LevelFormatter(
198 fmt={
199 "DEBUG": "%(log_color)s%(message)s (%(module)s:%(lineno)d)",
200 "INFO": "%(log_color)s%(message)s",
201 "WARNING": "%(log_color)sWRN: %(message)s (%(module)s:%(lineno)d)",
202 "ERROR": "%(log_color)sERR: %(message)s (%(module)s:%(lineno)d)",
203 "CRITICAL": "%(log_color)sCRT: %(message)s (%(module)s:%(lineno)d)",
204 }
205 )
206 """
207 self.formatters = {
208 level: ColoredFormatter(fmt=f, **kwargs) for level, f in fmt.items()
209 }
210
211 def format(self, record: logging.LogRecord) -> str:
212 return self.formatters[record.levelname].format(record)
213
214
215# Provided for backwards compatibility. The features provided by this subclass are now
216# included directly in the `ColoredFormatter` class.
217TTYColoredFormatter = ColoredFormatter