我們知道**代表次方。
>>>12 * 12 144 >>>12 ** 2 144 >>>a=1e200 >>> a 1e+200 >>>a ** 2 Traceback (most recent call last): File "stdin>", line 1, in module> OverflowError: (34, 'Result too large') >>>a * a inf >>>a = 100 ** 100 # python3中int整型一般不會溢出,取決于內(nèi)存 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 >>>a * a,a ** 2 # 兩種方式都沒問題,int很大,不會溢出,取決于內(nèi)存 (10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000, 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) >>>float(a) * float(a) #float用這種方法,也不會溢出 inf >>>float(a) ** 2 #float用這種方式有可能溢出,注意?。?! Traceback (most recent call last): File "stdin>", line 1, in module> OverflowError: (34, 'Result too large')
補充:python3.8中運算符/和//區(qū)別
5/5的結(jié)果為1.0,5//5的結(jié)果為1
6.0/5.0的結(jié)果為1.2,6.0//5.0的結(jié)果為1.0
由此可見,使用/運算符時,即使兩參數(shù)都是int,返回值都是float,而運算符//只有當參數(shù)中含有float時,返回值是float,但是結(jié)果是取整的。
//運算符的結(jié)果是最小取整的,/運算符會保留小數(shù)位
補充:python3中運算符及其優(yōu)先級
+ - * /(真除法) % //(地板除-floor) **(冪運算)
=
+= -= *= /= %= **= //=
a+=1 (運行效率高)
a=a+1 (運行效率低)
== > >= = !=
可以連續(xù)判斷:
3>2>1
True
3>2 and 2>1
True
not and or 優(yōu)先級:
not優(yōu)先級最高
and
or 優(yōu)先級最低
位:二進制下的每一個位
>> :移位運算符
:邏輯求與
|:邏輯求或
~:邏輯求非
^:邏輯求異或
變量=(值1 if 布爾表達式 else 值2)
如果布爾表達式位真則返回值1否則返回值2
運算符中,三元運算符的優(yōu)先級最低
1. 先乘除后加減
2. 冪運算優(yōu)先級最高
3. 三元運算符優(yōu)先級最低
4. 元數(shù)越少,優(yōu)先級越高
冪運算:一元運算符
5. 優(yōu)先級從高到低排列:
冪運算
正負號
算數(shù)運算符(— = * /)
比較運算符( > = >=)
邏輯運算符(not and or)
以上為個人經(jīng)驗,希望能給大家一個參考,也希望大家多多支持腳本之家。