python 数学操作符

  

优先级从高到低

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print("2 ** 3 = %d" % 2 ** 3)      2 ** 3 = 8
print("7 % 2 = {}".format(7 % 2))  7 % 2 = 1
print('7 %% 2 = %d' % (7 % 2))     7 % 2 = 1
print("7 // 2 = %d" % (7 // 2))    7 // 2 = 3
print("7 / 2 = %s" % (7 / 2))      7 / 2 = 3.5
print("2 * 3 = %d" % (2 * 3))　　  2 * 3 = 6
print("2 * 3 = %d" % 2 * 3)        2 * 3 = 22 * 3 = 22 * 3 = 2
print("3 - 2 = %d" % (3 - 2))      3 - 2 = 1
print("3 + 2 = %d" % (3 + 2))　　　3 + 2 = 5

优先级的重要性，操作符的执行顺序从左到右

没有加括号，执行结果是不一样的

print("2 * 3 = %d" % 2 * 3)        2 * 3 = 22 * 3 = 22 * 3 = 2

print("2 * 3 = %d" % (2 * 3))　　　 2 * 3 = 6

+、-、*、/、//、%和**是数学操作符，+和*是字符串操作符