Note 13 - Capital Stock - Continuity Schedule of Outstanding Share Purchase Warrants (Details) - $ / shares	12 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Balance, Number of Warrants (in shares)	7,721,981	19,443,910
Balance, Weighted Average Exercise Price (in dollars per share)	$ 2.03	$ 1.94
Issued, Number of Warrants (in shares)		300,000
Issued, Weighted Average Exercise Price (in dollars per share)		$ 1.38
Expired, Number of Warrants (in shares)	(1,109,304)	(12,021,929)
Expired (in dollars per share)	$ 1.87	$ 1.87
Exercised, Number of Warrants (in shares)	(8,240,505)
Exercised, Weighted Average Exercise Price (in dollars per share)	$ 1.99
Balance, Number of Warrants (in shares)	5,387,323	7,721,981
Balance, Weighted Average Exercise Price (in dollars per share)	$ 1.90	$ 2.03
September 2020 Offering [Member]
Issued, Number of Warrants (in shares)	6,833,333
Issued, Weighted Average Exercise Price (in dollars per share)	$ 1.80
April 2021 Offering [Member]
Issued, Number of Warrants (in shares)	181,818
Issued, Weighted Average Exercise Price (in dollars per share)	$ 4.13