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Diffstat (limited to 'Lib/wsgiref/headers.py')
| -rw-r--r-- | Lib/wsgiref/headers.py | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/Lib/wsgiref/headers.py b/Lib/wsgiref/headers.py new file mode 100644 index 0000000..016eb86 --- /dev/null +++ b/Lib/wsgiref/headers.py @@ -0,0 +1,205 @@ +"""Manage HTTP Response Headers + +Much of this module is red-handedly pilfered from email.Message in the stdlib, +so portions are Copyright (C) 2001,2002 Python Software Foundation, and were +written by Barry Warsaw. +""" + +from types import ListType, TupleType + +# Regular expression that matches `special' characters in parameters, the +# existance of which force quoting of the parameter value. +import re +tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]') + +def _formatparam(param, value=None, quote=1): + """Convenience function to format and return a key=value pair. + + This will quote the value if needed or if quote is true. + """ + if value is not None and len(value) > 0: + if quote or tspecials.search(value): + value = value.replace('\\', '\\\\').replace('"', r'\"') + return '%s="%s"' % (param, value) + else: + return '%s=%s' % (param, value) + else: + return param + + + + + + + + + + + + + + +class Headers: + + """Manage a collection of HTTP response headers""" + + def __init__(self,headers): + if type(headers) is not ListType: + raise TypeError("Headers must be a list of name/value tuples") + self._headers = headers + + def __len__(self): + """Return the total number of headers, including duplicates.""" + return len(self._headers) + + def __setitem__(self, name, val): + """Set the value of a header.""" + del self[name] + self._headers.append((name, val)) + + def __delitem__(self,name): + """Delete all occurrences of a header, if present. + + Does *not* raise an exception if the header is missing. + """ + name = name.lower() + self._headers[:] = [kv for kv in self._headers if kv[0].lower()<>name] + + def __getitem__(self,name): + """Get the first header value for 'name' + + Return None if the header is missing instead of raising an exception. + + Note that if the header appeared multiple times, the first exactly which + occurrance gets returned is undefined. Use getall() to get all + the values matching a header field name. + """ + return self.get(name) + + + + + + def has_key(self, name): + """Return true if the message contains the header.""" + return self.get(name) is not None + + __contains__ = has_key + + + def get_all(self, name): + """Return a list of all the values for the named field. + + These will be sorted in the order they appeared in the original header + list or were added to this instance, and may contain duplicates. Any + fields deleted and re-inserted are always appended to the header list. + If no fields exist with the given name, returns an empty list. + """ + name = name.lower() + return [kv[1] for kv in self._headers if kv[0].lower()==name] + + + def get(self,name,default=None): + """Get the first header value for 'name', or return 'default'""" + name = name.lower() + for k,v in self._headers: + if k.lower()==name: + return v + return default + + + def keys(self): + """Return a list of all the header field names. + + These will be sorted in the order they appeared in the original header + list, or were added to this instance, and may contain duplicates. + Any fields deleted and re-inserted are always appended to the header + list. + """ + return [k for k, v in self._headers] + + + + + def values(self): + """Return a list of all header values. + + These will be sorted in the order they appeared in the original header + list, or were added to this instance, and may contain duplicates. + Any fields deleted and re-inserted are always appended to the header + list. + """ + return [v for k, v in self._headers] + + def items(self): + """Get all the header fields and values. + + These will be sorted in the order they were in the original header + list, or were added to this instance, and may contain duplicates. + Any fields deleted and re-inserted are always appended to the header + list. + """ + return self._headers[:] + + def __repr__(self): + return "Headers(%s)" % `self._headers` + + def __str__(self): + """str() returns the formatted headers, complete with end line, + suitable for direct HTTP transmission.""" + return '\r\n'.join(["%s: %s" % kv for kv in self._headers]+['','']) + + def setdefault(self,name,value): + """Return first matching header value for 'name', or 'value' + + If there is no header named 'name', add a new header with name 'name' + and value 'value'.""" + result = self.get(name) + if result is None: + self._headers.append((name,value)) + return value + else: + return result + + + def add_header(self, _name, _value, **_params): + """Extended header setting. + + _name is the header field to add. keyword arguments can be used to set + additional parameters for the header field, with underscores converted + to dashes. Normally the parameter will be added as key="value" unless + value is None, in which case only the key will be added. + + Example: + + h.add_header('content-disposition', 'attachment', filename='bud.gif') + + Note that unlike the corresponding 'email.Message' method, this does + *not* handle '(charset, language, value)' tuples: all values must be + strings or None. + """ + parts = [] + if _value is not None: + parts.append(_value) + for k, v in _params.items(): + if v is None: + parts.append(k.replace('_', '-')) + else: + parts.append(_formatparam(k.replace('_', '-'), v)) + self._headers.append((_name, "; ".join(parts))) + + + + + + + + + + + + + + + +# |