JezK
Edit File: extract.py
""" babel.messages.extract ~~~~~~~~~~~~~~~~~~~~~~ Basic infrastructure for extracting localizable messages from source files. This module defines an extensible system for collecting localizable message strings from a variety of sources. A native extractor for Python source files is builtin, extractors for other sources can be added using very simple plugins. The main entry points into the extraction functionality are the functions `extract_from_dir` and `extract_from_file`. :copyright: (c) 2013-2022 by the Babel Team. :license: BSD, see LICENSE for more details. """ import os from os.path import relpath import sys from tokenize import generate_tokens, COMMENT, NAME, OP, STRING from babel.util import parse_encoding, parse_future_flags, pathmatch from textwrap import dedent GROUP_NAME = 'babel.extractors' DEFAULT_KEYWORDS = { '_': None, 'gettext': None, 'ngettext': (1, 2), 'ugettext': None, 'ungettext': (1, 2), 'dgettext': (2,), 'dngettext': (2, 3), 'N_': None, 'pgettext': ((1, 'c'), 2), 'npgettext': ((1, 'c'), 2, 3) } DEFAULT_MAPPING = [('**.py', 'python')] empty_msgid_warning = ( '%s: warning: Empty msgid. It is reserved by GNU gettext: gettext("") ' 'returns the header entry with meta information, not the empty string.') def _strip_comment_tags(comments, tags): """Helper function for `extract` that strips comment tags from strings in a list of comment lines. This functions operates in-place. """ def _strip(line): for tag in tags: if line.startswith(tag): return line[len(tag):].strip() return line comments[:] = map(_strip, comments) def default_directory_filter(dirpath): subdir = os.path.basename(dirpath) # Legacy default behavior: ignore dot and underscore directories return not (subdir.startswith('.') or subdir.startswith('_')) def extract_from_dir( dirname=None, method_map=DEFAULT_MAPPING, options_map=None, keywords=DEFAULT_KEYWORDS, comment_tags=(), callback=None, strip_comment_tags=False, directory_filter=None, ): """Extract messages from any source files found in the given directory. This function generates tuples of the form ``(filename, lineno, message, comments, context)``. Which extraction method is used per file is determined by the `method_map` parameter, which maps extended glob patterns to extraction method names. For example, the following is the default mapping: >>> method_map = [ ... ('**.py', 'python') ... ] This basically says that files with the filename extension ".py" at any level inside the directory should be processed by the "python" extraction method. Files that don't match any of the mapping patterns are ignored. See the documentation of the `pathmatch` function for details on the pattern syntax. The following extended mapping would also use the "genshi" extraction method on any file in "templates" subdirectory: >>> method_map = [ ... ('**/templates/**.*', 'genshi'), ... ('**.py', 'python') ... ] The dictionary provided by the optional `options_map` parameter augments these mappings. It uses extended glob patterns as keys, and the values are dictionaries mapping options names to option values (both strings). The glob patterns of the `options_map` do not necessarily need to be the same as those used in the method mapping. For example, while all files in the ``templates`` folders in an application may be Genshi applications, the options for those files may differ based on extension: >>> options_map = { ... '**/templates/**.txt': { ... 'template_class': 'genshi.template:TextTemplate', ... 'encoding': 'latin-1' ... }, ... '**/templates/**.html': { ... 'include_attrs': '' ... } ... } :param dirname: the path to the directory to extract messages from. If not given the current working directory is used. :param method_map: a list of ``(pattern, method)`` tuples that maps of extraction method names to extended glob patterns :param options_map: a dictionary of additional options (optional) :param keywords: a dictionary mapping keywords (i.e. names of functions that should be recognized as translation functions) to tuples that specify which of their arguments contain localizable strings :param comment_tags: a list of tags of translator comments to search for and include in the results :param callback: a function that is called for every file that message are extracted from, just before the extraction itself is performed; the function is passed the filename, the name of the extraction method and and the options dictionary as positional arguments, in that order :param strip_comment_tags: a flag that if set to `True` causes all comment tags to be removed from the collected comments. :param directory_filter: a callback to determine whether a directory should be recursed into. Receives the full directory path; should return True if the directory is valid. :see: `pathmatch` """ if dirname is None: dirname = os.getcwd() if options_map is None: options_map = {} if directory_filter is None: directory_filter = default_directory_filter absname = os.path.abspath(dirname) for root, dirnames, filenames in os.walk(absname): dirnames[:] = [ subdir for subdir in dirnames if directory_filter(os.path.join(root, subdir)) ] dirnames.sort() filenames.sort() for filename in filenames: filepath = os.path.join(root, filename).replace(os.sep, '/') yield from check_and_call_extract_file( filepath, method_map, options_map, callback, keywords, comment_tags, strip_comment_tags, dirpath=absname, ) def check_and_call_extract_file(filepath, method_map, options_map, callback, keywords, comment_tags, strip_comment_tags, dirpath=None): """Checks if the given file matches an extraction method mapping, and if so, calls extract_from_file. Note that the extraction method mappings are based relative to dirpath. So, given an absolute path to a file `filepath`, we want to check using just the relative path from `dirpath` to `filepath`. Yields 5-tuples (filename, lineno, messages, comments, context). :param filepath: An absolute path to a file that exists. :param method_map: a list of ``(pattern, method)`` tuples that maps of extraction method names to extended glob patterns :param options_map: a dictionary of additional options (optional) :param callback: a function that is called for every file that message are extracted from, just before the extraction itself is performed; the function is passed the filename, the name of the extraction method and and the options dictionary as positional arguments, in that order :param keywords: a dictionary mapping keywords (i.e. names of functions that should be recognized as translation functions) to tuples that specify which of their arguments contain localizable strings :param comment_tags: a list of tags of translator comments to search for and include in the results :param strip_comment_tags: a flag that if set to `True` causes all comment tags to be removed from the collected comments. :param dirpath: the path to the directory to extract messages from. :return: iterable of 5-tuples (filename, lineno, messages, comments, context) :rtype: Iterable[tuple[str, int, str|tuple[str], list[str], str|None] """ # filename is the relative path from dirpath to the actual file filename = relpath(filepath, dirpath) for pattern, method in method_map: if not pathmatch(pattern, filename): continue options = {} for opattern, odict in options_map.items(): if pathmatch(opattern, filename): options = odict if callback: callback(filename, method, options) for message_tuple in extract_from_file( method, filepath, keywords=keywords, comment_tags=comment_tags, options=options, strip_comment_tags=strip_comment_tags ): yield (filename, ) + message_tuple break def extract_from_file(method, filename, keywords=DEFAULT_KEYWORDS, comment_tags=(), options=None, strip_comment_tags=False): """Extract messages from a specific file. This function returns a list of tuples of the form ``(lineno, message, comments, context)``. :param filename: the path to the file to extract messages from :param method: a string specifying the extraction method (.e.g. "python") :param keywords: a dictionary mapping keywords (i.e. names of functions that should be recognized as translation functions) to tuples that specify which of their arguments contain localizable strings :param comment_tags: a list of translator tags to search for and include in the results :param strip_comment_tags: a flag that if set to `True` causes all comment tags to be removed from the collected comments. :param options: a dictionary of additional options (optional) :returns: list of tuples of the form ``(lineno, message, comments, context)`` :rtype: list[tuple[int, str|tuple[str], list[str], str|None] """ if method == 'ignore': return [] with open(filename, 'rb') as fileobj: return list(extract(method, fileobj, keywords, comment_tags, options, strip_comment_tags)) def extract(method, fileobj, keywords=DEFAULT_KEYWORDS, comment_tags=(), options=None, strip_comment_tags=False): """Extract messages from the given file-like object using the specified extraction method. This function returns tuples of the form ``(lineno, message, comments, context)``. The implementation dispatches the actual extraction to plugins, based on the value of the ``method`` parameter. >>> source = b'''# foo module ... def run(argv): ... print(_('Hello, world!')) ... ''' >>> from io import BytesIO >>> for message in extract('python', BytesIO(source)): ... print(message) (3, u'Hello, world!', [], None) :param method: an extraction method (a callable), or a string specifying the extraction method (.e.g. "python"); if this is a simple name, the extraction function will be looked up by entry point; if it is an explicit reference to a function (of the form ``package.module:funcname`` or ``package.module.funcname``), the corresponding function will be imported and used :param fileobj: the file-like object the messages should be extracted from :param keywords: a dictionary mapping keywords (i.e. names of functions that should be recognized as translation functions) to tuples that specify which of their arguments contain localizable strings :param comment_tags: a list of translator tags to search for and include in the results :param options: a dictionary of additional options (optional) :param strip_comment_tags: a flag that if set to `True` causes all comment tags to be removed from the collected comments. :raise ValueError: if the extraction method is not registered :returns: iterable of tuples of the form ``(lineno, message, comments, context)`` :rtype: Iterable[tuple[int, str|tuple[str], list[str], str|None] """ func = None if callable(method): func = method elif ':' in method or '.' in method: if ':' not in method: lastdot = method.rfind('.') module, attrname = method[:lastdot], method[lastdot + 1:] else: module, attrname = method.split(':', 1) func = getattr(__import__(module, {}, {}, [attrname]), attrname) else: try: from pkg_resources import working_set except ImportError: pass else: for entry_point in working_set.iter_entry_points(GROUP_NAME, method): func = entry_point.load(require=True) break if func is None: # if pkg_resources is not available or no usable egg-info was found # (see #230), we resort to looking up the builtin extractors # directly builtin = { 'ignore': extract_nothing, 'python': extract_python, 'javascript': extract_javascript } func = builtin.get(method) if func is None: raise ValueError('Unknown extraction method %r' % method) results = func(fileobj, keywords.keys(), comment_tags, options=options or {}) for lineno, funcname, messages, comments in results: if funcname: spec = keywords[funcname] or (1,) else: spec = (1,) if not isinstance(messages, (list, tuple)): messages = [messages] if not messages: continue # Validate the messages against the keyword's specification context = None msgs = [] invalid = False # last_index is 1 based like the keyword spec last_index = len(messages) for index in spec: if isinstance(index, tuple): context = messages[index[0] - 1] continue if last_index < index: # Not enough arguments invalid = True break message = messages[index - 1] if message is None: invalid = True break msgs.append(message) if invalid: continue # keyword spec indexes are 1 based, therefore '-1' if isinstance(spec[0], tuple): # context-aware *gettext method first_msg_index = spec[1] - 1 else: first_msg_index = spec[0] - 1 if not messages[first_msg_index]: # An empty string msgid isn't valid, emit a warning where = '%s:%i' % (hasattr(fileobj, 'name') and fileobj.name or '(unknown)', lineno) sys.stderr.write((empty_msgid_warning % where) + '\n') continue messages = tuple(msgs) if len(messages) == 1: messages = messages[0] if strip_comment_tags: _strip_comment_tags(comments, comment_tags) yield lineno, messages, comments, context def extract_nothing(fileobj, keywords, comment_tags, options): """Pseudo extractor that does not actually extract anything, but simply returns an empty list. """ return [] def extract_python(fileobj, keywords, comment_tags, options): """Extract messages from Python source code. It returns an iterator yielding tuples in the following form ``(lineno, funcname, message, comments)``. :param fileobj: the seekable, file-like object the messages should be extracted from :param keywords: a list of keywords (i.e. function names) that should be recognized as translation functions :param comment_tags: a list of translator tags to search for and include in the results :param options: a dictionary of additional options (optional) :rtype: ``iterator`` """ funcname = lineno = message_lineno = None call_stack = -1 buf = [] messages = [] translator_comments = [] in_def = in_translator_comments = False comment_tag = None encoding = parse_encoding(fileobj) or options.get('encoding', 'UTF-8') future_flags = parse_future_flags(fileobj, encoding) next_line = lambda: fileobj.readline().decode(encoding) tokens = generate_tokens(next_line) for tok, value, (lineno, _), _, _ in tokens: if call_stack == -1 and tok == NAME and value in ('def', 'class'): in_def = True elif tok == OP and value == '(': if in_def: # Avoid false positives for declarations such as: # def gettext(arg='message'): in_def = False continue if funcname: message_lineno = lineno call_stack += 1 elif in_def and tok == OP and value == ':': # End of a class definition without parens in_def = False continue elif call_stack == -1 and tok == COMMENT: # Strip the comment token from the line value = value[1:].strip() if in_translator_comments and \ translator_comments[-1][0] == lineno - 1: # We're already inside a translator comment, continue appending translator_comments.append((lineno, value)) continue # If execution reaches this point, let's see if comment line # starts with one of the comment tags for comment_tag in comment_tags: if value.startswith(comment_tag): in_translator_comments = True translator_comments.append((lineno, value)) break elif funcname and call_stack == 0: nested = (tok == NAME and value in keywords) if (tok == OP and value == ')') or nested: if buf: messages.append(''.join(buf)) del buf[:] else: messages.append(None) if len(messages) > 1: messages = tuple(messages) else: messages = messages[0] # Comments don't apply unless they immediately preceed the # message if translator_comments and \ translator_comments[-1][0] < message_lineno - 1: translator_comments = [] yield (message_lineno, funcname, messages, [comment[1] for comment in translator_comments]) funcname = lineno = message_lineno = None call_stack = -1 messages = [] translator_comments = [] in_translator_comments = False if nested: funcname = value elif tok == STRING: # Unwrap quotes in a safe manner, maintaining the string's # encoding # https://sourceforge.net/tracker/?func=detail&atid=355470& # aid=617979&group_id=5470 code = compile('# coding=%s\n%s' % (str(encoding), value), '<string>', 'eval', future_flags) value = eval(code, {'__builtins__': {}}, {}) buf.append(value) elif tok == OP and value == ',': if buf: messages.append(''.join(buf)) del buf[:] else: messages.append(None) if translator_comments: # We have translator comments, and since we're on a # comma(,) user is allowed to break into a new line # Let's increase the last comment's lineno in order # for the comment to still be a valid one old_lineno, old_comment = translator_comments.pop() translator_comments.append((old_lineno + 1, old_comment)) elif call_stack > 0 and tok == OP and value == ')': call_stack -= 1 elif funcname and call_stack == -1: funcname = None elif tok == NAME and value in keywords: funcname = value def extract_javascript(fileobj, keywords, comment_tags, options): """Extract messages from JavaScript source code. :param fileobj: the seekable, file-like object the messages should be extracted from :param keywords: a list of keywords (i.e. function names) that should be recognized as translation functions :param comment_tags: a list of translator tags to search for and include in the results :param options: a dictionary of additional options (optional) Supported options are: * `jsx` -- set to false to disable JSX/E4X support. * `template_string` -- set to false to disable ES6 template string support. """ from babel.messages.jslexer import Token, tokenize, unquote_string funcname = message_lineno = None messages = [] last_argument = None translator_comments = [] concatenate_next = False encoding = options.get('encoding', 'utf-8') last_token = None call_stack = -1 dotted = any('.' in kw for kw in keywords) for token in tokenize( fileobj.read().decode(encoding), jsx=options.get("jsx", True), template_string=options.get("template_string", True), dotted=dotted ): if ( # Turn keyword`foo` expressions into keyword("foo") calls: funcname and # have a keyword... (last_token and last_token.type == 'name') and # we've seen nothing after the keyword... token.type == 'template_string' # this is a template string ): message_lineno = token.lineno messages = [unquote_string(token.value)] call_stack = 0 token = Token('operator', ')', token.lineno) if token.type == 'operator' and token.value == '(': if funcname: message_lineno = token.lineno call_stack += 1 elif call_stack == -1 and token.type == 'linecomment': value = token.value[2:].strip() if translator_comments and \ translator_comments[-1][0] == token.lineno - 1: translator_comments.append((token.lineno, value)) continue for comment_tag in comment_tags: if value.startswith(comment_tag): translator_comments.append((token.lineno, value.strip())) break elif token.type == 'multilinecomment': # only one multi-line comment may preceed a translation translator_comments = [] value = token.value[2:-2].strip() for comment_tag in comment_tags: if value.startswith(comment_tag): lines = value.splitlines() if lines: lines[0] = lines[0].strip() lines[1:] = dedent('\n'.join(lines[1:])).splitlines() for offset, line in enumerate(lines): translator_comments.append((token.lineno + offset, line)) break elif funcname and call_stack == 0: if token.type == 'operator' and token.value == ')': if last_argument is not None: messages.append(last_argument) if len(messages) > 1: messages = tuple(messages) elif messages: messages = messages[0] else: messages = None # Comments don't apply unless they immediately precede the # message if translator_comments and \ translator_comments[-1][0] < message_lineno - 1: translator_comments = [] if messages is not None: yield (message_lineno, funcname, messages, [comment[1] for comment in translator_comments]) funcname = message_lineno = last_argument = None concatenate_next = False translator_comments = [] messages = [] call_stack = -1 elif token.type in ('string', 'template_string'): new_value = unquote_string(token.value) if concatenate_next: last_argument = (last_argument or '') + new_value concatenate_next = False else: last_argument = new_value elif token.type == 'operator': if token.value == ',': if last_argument is not None: messages.append(last_argument) last_argument = None else: messages.append(None) concatenate_next = False elif token.value == '+': concatenate_next = True elif call_stack > 0 and token.type == 'operator' \ and token.value == ')': call_stack -= 1 elif funcname and call_stack == -1: funcname = None elif call_stack == -1 and token.type == 'name' and \ token.value in keywords and \ (last_token is None or last_token.type != 'name' or last_token.value != 'function'): funcname = token.value last_token = token