我正在编写一个代码,要求用户提供一个百分比,并一直询问用户是否输入了可接受的输入。但是,当我运行此命令时,无论我输入哪种输入,while循环都不会中断。
这是我的代码:
import math
while True:
try:
entered = float(raw_input("Please enter the velocity (as a percentage of the speed of light): "))
except ValueError:
print("Sorry, an acceptable input was not entered. Try again.")
continue
if entered > 100:
print("Sorry, a velocity greater than the speed of light cannot be used. Try again.")
continue
elif entered <= 0:
print("Sorry, a percent cannot be negative. Try again.")
continue
else:
#the percent entered is valid, break out of while loop
break
print("Ship is traveling at ", entered, "% the speed of light.")
print(" ")
speedOfLight = 299792458 #speed of light constant
percentage = entered / 100 #turn entered percent into decimal
speed = speedOfLight * percentage #actual speed (in m/s)
denominator = math.sqrt(1 - (percentage ** 2)) #denominator of factor equation
factor = 1 / denominator #solve for given factor equation
shipWeight = 70000 * factor #given ship weight * factor
alphaCentauri = 4.3 / factor # given times divided by the factor
barnardsStar = 6.0 / factor
betelgeuse = 309 /factor
andromeda = 2000000 / factor
print("At this speed: ")
print(" Weight of the shuttle is ", shipWeight)
print(" Perceived time to travel to Alpha Centauri is ", alphaCentauri, " years.")
print(" Perceived time to travel to Barnard's Star is ", barnardsStar, " years.")
print(" Perceived time to travel to Betelgeuse is ", betelgeuse, " years.")
print(" Perceived time to travel to Andromeda Galaxy is ", andromeda, " years.")
最佳答案
您的缩进有点奇怪,并且代码从未到达break
语句,因为在此之前您对循环进行了continue
。幸运的是,您可以使用and else
关键字使其工作:
while True:
try:
entered = float(raw_input("Please enter the velocity (as a percentage of the speed of light): "))
except ValueError:
print("Sorry, an acceptable input was not entered. Try again.")
continue
else: # no exception
if entered > 100:
print("Sorry, a velocity greater than the speed of light cannot be used. Try again.")
continue
elif entered <= 0:
print("Sorry, a percent cannot be negative. Try again.")
continue
else:
#the percent entered is valid, break out of while loop
break
关于python - while循环在Python中连续运行,输入好还是不好?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36323373/