Note 12 - Derivative Liabilities - Assumptions (Details)	Apr. 30, 2023 $ / shares	Jan. 31, 2023 $ / shares	Oct. 31, 2022 $ / shares	Jul. 31, 2022 $ / shares
Exercise Price in U.S. dollars (in dollars per share)	$ 2.88	$ 2.93	$ 2.85	$ 1.92
Replacement Warrants [Member] | Measurement Input, Expected Dividend Rate [Member]
Derivative, measurement input	0.0000
Replacement Warrants [Member] | Minimum [Member]
Exercise Price in U.S. dollars (in dollars per share)	$ 1.06
Replacement Warrants [Member] | Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Derivative, measurement input	0.0404
Replacement Warrants [Member] | Minimum [Member] | Measurement Input, Price Volatility [Member]
Derivative, measurement input	0.4120
Replacement Warrants [Member] | Minimum [Member] | Measurement Input, Expected Term [Member]
Derivative, measurement input	0.05
Replacement Warrants [Member] | Maximum [Member]
Exercise Price in U.S. dollars (in dollars per share)	$ 3.27
Replacement Warrants [Member] | Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Derivative, measurement input	0.0448
Replacement Warrants [Member] | Maximum [Member] | Measurement Input, Price Volatility [Member]
Derivative, measurement input	0.8393
Replacement Warrants [Member] | Maximum [Member] | Measurement Input, Expected Term [Member]
Derivative, measurement input	1.36