Note 10 - Long-term Debt (Details Textual)	3 Months Ended				9 Months Ended
	Apr. 30, 2021 USD ($)	Jan. 31, 2021 USD ($)	Apr. 30, 2020 USD ($)	Jan. 31, 2020 USD ($)	Apr. 30, 2021 USD ($) shares	Apr. 30, 2020 USD ($)	Jul. 31, 2020 USD ($)
Amortization of Debt Discount (Premium)					$ 1,122,096	$ 1,244,032
Stock Issued During Period, Shares, Credit Facility (in shares) | shares					1,249,039
Stock Issued During Period, Value, Credit Facility		$ 1,170,000		$ 1,400,000	$ 1,170,000
Percentage of Outstanding Principal of Anniversary Fee					6.50%
Working Capital Ratio					32
Credit Agreement [Member]
Amortization of Debt Discount (Premium)	$ 296,401		$ 399,231		$ 1,122,096	1,244,032
Interest Paid, Including Capitalized Interest, Operating and Investing Activities, Total	274,222		$ 400,000		1,051,111	$ 1,217,778
Repayments of Long-term Debt, Total					10,000,000
Long-term Debt, Gross	$ 10,000,000	$ 18,000,000			$ 10,000,000		$ 20,000,000
Debt Instrument, Interest Rate, Stated Percentage	8.00%				8.00%
Debt Instrument, Interest Rate, Effective Percentage	18.10%				18.10%
Debt Instrument, Covenant, Minimum Working Capital Ratio	1				1