multiprocessing.set_start_method(method) Set the method which should be used to start child processes. method can be 'fork', 'spawn' or 'forkserver'. Note that this should be called at most once, and it should be protected inside the if __name__ == '__main__' clause of the main module. New in version 3.4.

strides A tuple of integers the length of ndim giving the size in bytes to access each element for each dimension of the array. Changed in version 3.3: An empty tuple instead of None when ndim = 0.

math.gcd(a, b) Return the greatest common divisor of the integers a and b. If either a or b is nonzero, then the value of gcd(a, b) is the largest positive integer that divides both a and b. gcd(0, 0) returns 0. New in version 3.5.

symmetric_difference_update(other) set ^= other Update the set, keeping only elements found in either set, but not in both.

turtle.penup() turtle.pu() turtle.up() Pull the pen up – no drawing when moving.

exception smtplib.SMTPResponseException Base class for all exceptions that include an SMTP error code. These exceptions are generated in some instances when the SMTP server returns an error code. The error code is stored in the smtp_code attribute of the error, and the smtp_error attribute is set to the error message.

set_sequences(sequences) Re-define the sequences that exist in the mailbox based upon sequences, a dictionary of names mapped to key lists, like returned by get_sequences().

operator.imatmul(a, b) operator.__imatmul__(a, b) a = imatmul(a, b) is equivalent to a @= b. New in version 3.5.

class queue.LifoQueue(maxsize=0) Constructor for a LIFO queue. maxsize is an integer that sets the upperbound limit on the number of items that can be placed in the queue. Insertion will block once this size has been reached, until queue items are consumed. If maxsize is less than or equal to zero, the queue size is infinite.

turtle.clearstamps(n=None) Parameters: n – an integer (or None) Delete all or first/last n of turtle’s stamps. If n is None, delete all stamps, if n > 0 delete first n stamps, else if n < 0 delete last n stamps. >>> for i in range(8): ... turtle.stamp(); turtle.fd(30) 13 14 15 16 17 18 19 20 >>> turtle.clearstamps(2) >>> turtle.clearstamps(-2) >>> turtle.clearstamps()