[pipenv.exceptions.ResolutionFailure]: Warning: Your dependencies could not be resolved. You likely have a mismatch in your sub-dependencies. You can use $ pipenv install --skip-lock to bypass this mechanism, then run $ pipenv graph to inspect the situation. Hint: try $ pipenv lock --pre if it is a pre-release dependency. ERROR: No matching distribution found for piprequests

Solution

pipenv install requests http://pypi.douban.com/simple/