def test_empty(self): for ex in ['', '1', '1+2', '1+3>2']: self.assertEquals(0, len(extract_var(ex)))
def test_basic(self): self.assertEquals(set(['x']), extract_var('x')) self.assertEquals(set(['x']), extract_var('x+x')) self.assertEquals(set(['x', 'y']), extract_var('x+y')) self.assertEquals(set(['x', 'y']), extract_var('x+1==y'))