Python的坑（1） -- 列表复制

list1 = [1,2,3]

list2 = [1,2,3]

a = list1[:]

b = list2

a b两种复制列表的方式的区别

先写个大概吧

最好别用第二种复制的方式，因为第二种复制方式，会带来很多问题，对b的操作，可能会改变list2,但是对a的操作不会改变list1。

抽空补充具体的例子，并且做详细说明。

def getAvailableLetters(lettersGuessed):
    '''
    lettersGuessed: list, what letters have been guessed so far
    returns: string, comprised of letters that represents what letters have not
      yet been guessed.
    '''
    # FILL IN YOUR CODE HERE...
    output = string.ascii_lowercase[:]
    for letter in lettersGuessed:
        if letter in string.ascii_lowercase:
            output = output.replace(letter, '')
    return output

测试用例：

Test 1 Function call: getAvailableLetters(['e', 'i', 'k', 'p', 'r', 's'])True Correct Result: 'abcdfghjlmnoqtuvwxyz'And Your Result: 'abcdfghjlmnoqtuvwxyz'------+------+------+------+------Test 2 Function call: getAvailableLetters([])False Correct Result: 'abcdefghijklmnopqrstuvwxyz'BUT Your Result: 'abcdfghjlmnoqtuvwxyz'------+------+------+------+------Random Test 1 Function call: getAvailableLetters(['n', 'e', 'p'])False Correct Result: 'abcdfghijklmoqrstuvwxyz'BUT Your Result: 'abcdfghjlmoqtuvwxyz'------+------+------+------+------Random Test 2 Function call: getAvailableLetters(['c', 'l', 'k', 'i', 'p'])False Correct Result: 'abdefghjmnoqrstuvwxyz'BUT Your Result: 'abdfghjmoqtuvwxyz'------+------+------+------+------Random Test 3 Function call: getAvailableLetters(['j', 'q', 'd', 'e', 'a', 'g', 'k'])False Correct Result: 'bcfhilmnoprstuvwxyz'BUT Your Result: 'bfhmotuvwxyz'------+------+------+------+------Random Test 4 Function call: getAvailableLetters(['z', 's', 'q', 'b', 'g', 'a'])False Correct Result: 'cdefhijklmnoprtuvwxy'BUT Your Result: 'fhmotuvwxy'------+------+------+------+------