Note 13 - Capital Stock - Warrants Outstanding and Exercisable (Details) - $ / shares	6 Months Ended
	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022
Weighted Average Exercise Price (in dollars per share)	$ 2.93	$ 2.85	$ 1.92
Number of Warrants Outstanding (in shares)	4,792,586	4,837,586	3,615,454
Weighted Average Remaining Contractual Life (Year)	1 year 4 months 28 days
Warrants 1 [Member]
Number of Warrants Outstanding (in shares)	144,194
Weighted Average Remaining Contractual Life (Year)	3 months 18 days
Warrants 2 [Member]
Number of Warrants Outstanding (in shares)	25,000
Weighted Average Remaining Contractual Life (Year)	3 months 18 days
Warrants 3 [Member]
Number of Warrants Outstanding (in shares)	766,362
Weighted Average Remaining Contractual Life (Year)	3 months 29 days
Warrants 4 [Member]
Number of Warrants Outstanding (in shares)	3,675,212
Weighted Average Remaining Contractual Life (Year)	1 year 7 months 6 days
Warrants 5 [Member]
Number of Warrants Outstanding (in shares)	181,818
Weighted Average Remaining Contractual Life (Year)	3 years 2 months 4 days