diff options
Diffstat (limited to 'Lib/rfc822.py')
| -rw-r--r-- | Lib/rfc822.py | 72 |
1 files changed, 48 insertions, 24 deletions
diff --git a/Lib/rfc822.py b/Lib/rfc822.py index 06b372a..9631def 100644 --- a/Lib/rfc822.py +++ b/Lib/rfc822.py @@ -13,13 +13,13 @@ sys.stdin or call os.popen(). Then pass the open file object to the Message() constructor: m = Message(fp) -This class can work with any input object that supports read and seek -methods. The initialization method which parses the message will work -even without seek capability, but in that case the final seek to the -start of the delimiter line won't take place. However, if the input -object has an `unread' method that can push back a line of input, -Message will use that to push back the delimiter line. Thus this class -can be used to parse messages coming from a buffered stream. +This class can work with any input object that supports a readline +method. If the input object has seek and tell capability, the +rewindbody method will work; also illegal lines will be pushed back +onto the input stream. If the input object lacks seek but has an +`unread' method that can push back a line of input, Message will use +that to push back illegal lines. Thus this class can be used to parse +messages coming from a buffered stream. The optional `seekable' argument is provided as a workaround for certain stdio libraries in which tell() discards buffered data before @@ -134,29 +134,30 @@ class Message: self.unixfrom = self.unixfrom + line continue firstline = 0 - if self.islast(line): - break - elif headerseen and line[0] in ' \t': + if headerseen and line[0] in ' \t': # It's a continuation line. list.append(line) - x = (self.dict[headerseen] + "\n " + - string.strip(line)) + x = (self.dict[headerseen] + "\n " + string.strip(line)) self.dict[headerseen] = string.strip(x) - elif ':' in line: - # It's a header line. - list.append(line) - i = string.find(line, ':') - headerseen = string.lower(line[:i]) - self.dict[headerseen] = string.strip( - line[i+1:]) + continue elif self.iscomment(line): - pass + # It's a comment. Ignore it. + continue + elif self.islast(line): + # Note! No pushback here! The delimiter line gets eaten. + break + headerseen = self.isheader(line) + if headerseen: + # It's a legal header line, save it. + list.append(line) + self.dict[headerseen] = string.strip(line[len(headerseen)+2:]) + continue else: - # It's not a header line; stop here. - if not headerseen: + # It's not a header line; throw it back and stop here. + if not self.dict: self.status = 'No headers' else: - self.status = 'Bad header' + self.status = 'Non-header line where header expected' # Try to undo the read. if getattr(self.fp, 'unread'): self.fp.unread(line) @@ -165,6 +166,19 @@ class Message: else: self.status = self.status + '; bad seek' break + + def isheader(self, line): + """Determine whether a given line is a legal header. + + This method should return the header name, suitably canonicalized. + You may override this method in order to use Message parsing + on tagged data in RFC822-like formats with special header formats. + """ + i = string.find(line, ':') + if i > 0: + return string.lower(line[:i]) + else: + return None def islast(self, line): """Determine whether a line is a legal end of RFC-822 headers. @@ -323,6 +337,15 @@ class Message: def __getitem__(self, name): """Get a specific header, as from a dictionary.""" return self.dict[string.lower(name)] + + def __setitem__(self, name, value): + """Set the value of a header.""" + del self[name] # Won't fail if it doesn't exist + self.dict[string.lower(name)] = value + text = name + ": " + value + lines = string.split(text, "\n") + for line in lines: + self.headers.append(line + "\n") def __delitem__(self, name): """Delete all occurrences of a specific header, if it is present.""" @@ -646,7 +669,8 @@ class AddrlistClass: """Parse a sequence of RFC-822 phrases. A phrase is a sequence of words, which are in turn either - RFC-822 atoms or quoted-strings. + RFC-822 atoms or quoted-strings. Phrases are canonicalized + by squeezing all runs of continuous whitespace into one space. """ plist = [] |