Note 9 - Net Income (Loss) Per Share - Components of Reconciliation of Numerators and Denominators Net Loss Per Share (Details) - USD ($)	3 Months Ended				6 Months Ended
	Apr. 30, 2021	Jan. 31, 2021	Apr. 30, 2020	Jan. 31, 2020	Apr. 30, 2021	Apr. 30, 2020
Net income (loss) (numerator)	$ 3,385,159	$ (2,141,480)	$ (1,689,181)	$ (2,591,888)	$ 1,243,679	$ (4,281,069)
Shares (denominator) (in shares)	7,536,116		7,350,427		7,536,121	7,351,897
Basic and diluted net income (loss) per share (in dollars per share)	$ 0.45		$ (0.23)		$ 0.17	$ (0.58)