ループはPythonで連続して実行されていますが、良い入力か悪いですか？

Question

こんにちは、これは初めてのPythonコードです。私はパーセンテージをユーザに尋ねるコードを書いており、受け入れ可能な入力がユーザによって入力されるまで質問を続ける。しかし、私がこれを実行すると、入力した入力の種類にかかわらずwhileループは中断しません。

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.") 

Answer 1

あなたのインデントが少しグラグラで、コードはbreakに達することはありませんあなたはcontinueの前にループしているからです。幸いにも、あなたはそれを動作させるためにキーワードを使用してelseことができます。

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 

Answer 2

あなたのexcept内のデータの入力をチェックしている：

は、ここに私のコードです。 floatへのキャストがValueErrorにならない限り、決してあなたの中に入ることはありません。

あなたは単にあなたがfloatキャストを渡すデータを確認することができますので、exceptブロックの外にあなたの条件を移動したい：

while True: 
    try: 
     entered = float(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 

Answer 3

あなたも/この仕事をするために壊し続ける必要はありません。また、whileループから抜け出すと、「数学を読み込む」必要があります。

あなたがする必要があるのは、インデントを見ることです。 try/exceptは、コードが実際にどのように記述されているかを反映していれば、あなたの決して終わっていないwhileループの原因となります。

以下だけインデントの修正及び「輸入数学」

import math 

valid = False 

while not valid: 
    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.") 
    elif entered <= 0: 
     print("Sorry, a percent cannot be negative. Try again.") 
    else: 
     #the percent entered is valid, break out of while loop 
      valid = True 

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.")