def test_missing_argument(script):
 result = script.pip('show', expect_error=True)
 assert ('ERROR: Please provide a package name or names.' in result.stderr)

def test_missing_argument ( script ) : result = script . pip ( 'show' , expect_error = True ) assert ( 'ERROR: Please provide a package name or names.' in result . stderr )
test show command with no arguments .