如何从列表中删除用户的输入？

Question

我正在处理此代码，但无法获取“ removeLetter”来删除用户从“选择”列表中选择的字母。 我发现我不能将列表函数与字符串一起使用，但是我不知道如何在不转换用户的字符串输入以匹配他/她想要的项目的情况下使start.remove（）代码正常工作从“选择”列表中删除。 有人能帮助我吗？

import random

oneList = "a ", "b ", "c "
twoList = "d ", "e ", "f "
threeList = "g ", "h ", "i "
fourList = "j ", "k ", "l "

# Selects a letter at random from each list
oneRandom = random.choice(oneList)
twoRandom = random.choice(twoList)
threeRandom = random.choice(threeList)
fourRandom = random.choice(fourList)

# Displays chosen letter from each list
print("These are your letters.")
chosen = oneRandom + twoRandom + threeRandom + fourRandom
print(chosen)

# First user input
start  = input("Would you like to remove a letter? y or n? ")

# If start = yes then do this.
if start == 'y':
    removeLetter = input("What letter would you like to remove? ")

    # Removes user's chosen letter.
    keptLetters = chosen.remove(removeLetter)

    # Displays kept letters.
    print(keptLetters)

Answer 1

您的代码中有错误，特别是在此行中：

keptLetters = start.remove (removeLetter)

您正在调用变量start但chosen的变量是带有字母列表的变量。 所以这应该工作：

keptLetters = chosen.remove (removeLetter)

Answer 2

您的代码中有几个问题。 我冒昧地为您提供了更多pythonic。

Python 2

import random

letter_sets = (("a", "b", "c"),
               ("d", "e", "f"),
               ("g", "h", "i"),
               ("j", "k", "l"))

# Selects a letter at random from each list
chosen = map(random.choice, letter_sets)

# Displays chosen letter from each list
print "These are your letters."
print " ".join(chosen)

# First user input
start = raw_input("Would you like to remove a letter? y or n?")

# If start = yes then do this.
if start[0].lower() == 'y':
    while(len(chosen) == 4): #Keep looping until a letter is chosen
        removeLetter = raw_input("What letter would you like to remove?")
        try:
            # Removes user's chosen letter.
            chosen.remove(removeLetter)
            # Displays kept letters.
            print " ".join(chosen)
        except ValueError: #If removeLetter is not in chosen
            print removeLetter, "is not in the list of letters"

Python 3

import random

letter_sets = (("a", "b", "c"),
               ("d", "e", "f"),
               ("g", "h", "i"),
               ("j", "k", "l"))

# Selects a letter at random from each list
chosen = list(map(random.choice, letter_sets))

# Displays chosen letter from each list
print("These are your letters.")
print(" ".join(chosen))

# First user input
start = input("Would you like to remove a letter? y or n?")

# If start = yes then do this.
if start[0].lower() == 'y':
    while(len(chosen) == 4): #Keep looping until a letter is chosen
        removeLetter = input("What letter would you like to remove?")
        try:
            # Removes user's chosen letter.
            chosen.remove(removeLetter)
            # Displays kept letters.
            print(" ".join(chosen))
        except ValueError: #If removeLetter is not in chosen
            print(removeLetter, "is not in the list of letters")

1. 拥有多个列表，并重复执行代码不是很Python。 因此，我将“列表”作为元组的元组（因为您可能不打算对其进行修改）。 如果是这样，则通过用方括号[]而不是括号()表示列表来更改列表。
2. 由于您要在多个列表上执行相同的操作，因此可以使用map()函数将所有结果都放入一个列表中。
3. chosen应该保留一个列表，而不是字符串，因为将来您将通过删除字母来对其进行操作。
4. 您可以轻松地join()所有在列表中的项目一起由单个空格分隔字符串" " 。
5. 由于list.remove()可以在值不在列表中时发回ValueError ，因此您需要在try..except块中进行处理。
6. 如果先前的尝试失败，可以用while循环包围您的逻辑，以不断要求删除一个字母。
7. chosen.remove更改了原始数组，因此您无需将其保存到keptLetters 。

我希望这可以帮助你！

编辑：添加了等效的Python 2代码

Answer 3

Je Pense que sa doitêtreça

import random oneList = "a ", "b ", "c "
twoList = "d ", "e ", "f " 
threeList = "g ", "h ", "i " 
fourList = "j ", "k ", "l " 
# Selects a letter at random from each list 
oneRandom = random.choice(oneList) 
twoRandom = random.choice(twoList) 
threeRandom = random.choice(threeList) 
fourRandom = random.choice(fourList) 
# Displays chosen letter from each list 
print("These are your letters.") chosen = oneRandom + twoRandom + threeRandom + fourRandom print(chosen) 
# First user input 
start = input("Would you like to remove a letter? y or n? ") 
# If start = yes then do this. 
if start == 'y': removeLetter = input("What letter would you like to remove? ") 
# Removes user's chosen letter. 
keptLetters = chosen.remove(removeLetter)
# Displays kept letters. 
print(keptLetters)