werkzeug.wsgi

Extracts the path info from the given URL (or WSGI environment) and path. The path info returned is a string. The URLs might also be IRIs.

If the path info could not be determined, None is returned.

Some examples:

>>> extract_path_info('http://example.com/app', '/app/hello')
'/hello'
>>> extract_path_info('http://example.com/app',
...                   'https://example.com/app/hello')
'/hello'
>>> extract_path_info('http://example.com/app',
...                   'https://example.com/app/hello',
...                   collapse_http_schemes=False) is None
True

Instead of providing a base URL you can also pass a WSGI environment.

Returns the content length from the WSGI environment as integer. If it's not available or chunked transfer encoding is used, None is returned.

Recreate the URL for a request from the parts in a WSGI environment.

The URL is an IRI, not a URI, so it may contain Unicode characters. Use ~werkzeug.urls.iri_to_uri to convert it to ASCII.

Return the host for the given WSGI environment.

The Host header is preferred, then SERVER_NAME if it's not set. The returned host will only contain the port if it is different than the standard port for the protocol.

Optionally, verify that the host is trusted using host_is_trusted and raise a ~werkzeug.exceptions.SecurityError if it is not.

Returns the input stream from the WSGI environment and wraps it in the most sensible way possible. The stream returned is not the raw WSGI stream in most cases but one that is safe to read from without taking into account the content length.

If content length is not set, the stream will be empty for safety reasons. If the WSGI server supports chunked or infinite streams, it should set the wsgi.input_terminated value in the WSGI environ to indicate that.

Return the PATH_INFO from the WSGI environment and decode it unless charset is None.

Returns the QUERY_STRING from the WSGI environment. This also takes care of the WSGI decoding dance. The string returned will be restricted to ASCII characters.

Return the SCRIPT_NAME from the WSGI environment and decode it unless charset is set to None.

Works like make_line_iter but accepts a separator which divides chunks. If you want newline based processing you should use make_line_iter instead as it supports arbitrary newline markers.

Safely iterates line-based over an input stream. If the input stream is not a LimitedStream the limit parameter is mandatory.

This uses the stream's ~file.read method internally as opposite to the ~file.readline method that is unsafe and can only be used in violation of the WSGI specification. The same problem applies to the __iter__ function of the input stream which calls ~file.readline without arguments.

If you need line-by-line processing it's strongly recommended to iterate over the input stream using this helper function.

Returns the next segment on the PATH_INFO or None if there is none. Works like pop_path_info without modifying the environment:

>>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
>>> peek_path_info(env)
'a'
>>> peek_path_info(env)
'a'

If the charset is set to None bytes are returned.

Removes and returns the next segment of PATH_INFO, pushing it onto SCRIPT_NAME. Returns None if there is nothing left on PATH_INFO.

If the charset is set to None bytes are returned.

If there are empty segments ('/foo//bar) these are ignored but properly pushed to the SCRIPT_NAME:

>>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
>>> pop_path_info(env)
'a'
>>> env['SCRIPT_NAME']
'/foo/a'
>>> pop_path_info(env)
'b'
>>> env['SCRIPT_NAME']
'/foo/a/b'

Marks a function as responder. Decorate a function with it and it will automatically call the return value as WSGI application.

Example:

@responder
def application(environ, start_response):
    return Response('Hello World!')

Wraps a file. This uses the WSGI server's file wrapper if available or otherwise the generic FileWrapper.

If the file wrapper from the WSGI server is used it's important to not iterate over it from inside the application but to pass it through unchanged. If you want to pass out a file wrapper inside a response object you have to set Response.direct_passthrough to True.

More information about file wrappers are available in PEP 333.