小數絆倒計劃

Question

Battery_Initial = raw_input("Enter Current Capacity:")) 

if Battery_Initial < 0: 
    print 'Battery Reading Malfunction' 

elif Battery_Initial > 80: 
    print 'Battery Reading Malfunction' 

這是我的計劃至今。我想知道是否有一種方法只允許0.5,1.0,1.5等輸入，基本上以0.5的間隔。

Answer 1

您需要使用float()而不是int()，因爲int()期望十進制輸入不會浮動。

Battery_Initial = float(raw_input("Enter Current Capacity:")) 

輸出：

$ python so27.py 
Enter Current Capacity:0.5 

$ python so27.py 
Enter Current Capacity:81.1 
Battery Reading Malfunction 

$ python so27.py 
Enter Current Capacity:-1.2 
Battery Reading Malfunction 

$ python so27.py 
Enter Current Capacity:-1 
Battery Reading Malfunction 

使用這樣的事情：

In [271]: [i/float(2) for i in range(1,10)] 
Out[271]: [0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5] 

用法：

if Battery_Initial in (i/float(2) for i in range(1,10)): 
     #do something here 

或按照@Joran Beasley的建議：

if Battery_Initial % 0.5 ==0: 
    #do something here