Note 14 - Stock-based Compensation - Schedule of Outstanding Unvested Stock Options (Details) - $ / shares	12 Months Ended
	Jul. 31, 2021	Jul. 30, 2021	Jul. 31, 2020
Nonvested balance (in shares)	6,797,471	6,797,471	3,310,600
Nonvested, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 0.46	$ 0.46	$ 0.59
Granted, number of stock options (in shares)	959,588	959,588	6,163,900
Granted, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 1.30		$ 0.45
Vested (in shares)		(3,865,852)	(2,590,154)
Vested, Weighted Average Grant-Date Fair Value (in dollars per share)	0.47		$ 0.60
Cancelled/Forfeited (in shares)			(86,875)
Cancelled/Forfeited, Weighted Average Grant-Date Fair Value (in dollars per share)			$ 0.43
Nonvested balance (in shares)		3,891,207	6,797,471
Nonvested, Weighted Average Grant-Date Fair Value (in dollars per share)	$ 0.66		$ 0.46