exception KeyError Raised when a mapping (dictionary) key is not found in the set of existing keys.

os.fchdir(fd) Change the current working directory to the directory represented by the file descriptor fd. The descriptor must refer to an opened directory, not an open file. As of Python 3.3, this is equivalent to os.chdir(fd). Availability: Unix.

Decompress.unconsumed_tail A bytes object that contains any data that was not consumed by the last decompress() call because it exceeded the limit for the uncompressed data buffer. This data has not yet been seen by the zlib machinery, so you must feed it (possibly with further data concatenated to it) back to a subsequent decompress() method call in order to get correct output.

bytes.count(sub[, start[, end]]) bytearray.count(sub[, start[, end]]) Return the number of non-overlapping occurrences of subsequence sub in the range [start, end]. Optional arguments start and end are interpreted as in slice notation. The subsequence to search for may be any bytes-like object or an integer in the range 0 to 255. Changed in version 3.3: Also accept an integer in the range 0 to 255 as the subsequence.

ProxyBasicAuthHandler.http_error_407(req, fp, code, msg, hdrs) Retry the request with authentication information, if available.

wsgiref.util.request_uri(environ, include_query=True) Return the full request URI, optionally including the query string, using the algorithm found in the “URL Reconstruction” section of PEP 3333. If include_query is false, the query string is not included in the resulting URI.

mapping(event, attribute) Make an entry into the EventMapping table for this control.

fail(msg=None) Signals a test failure unconditionally, with msg or None for the error message.

class decimal.InvalidOperation An invalid operation was performed. Indicates that an operation was requested that does not make sense. If not trapped, returns NaN. Possible causes include: Infinity - Infinity 0 * Infinity Infinity / Infinity x % 0 Infinity % x sqrt(-x) and x > 0 0 ** 0 x ** (non-integer) x ** Infinity

ast.iter_child_nodes(node) Yield all direct child nodes of node, that is, all fields that are nodes and all items of fields that are lists of nodes.