Question

我用它来删除列表中的非字母字符

alphabet = -1
int(alphabet)
while alphabet != howlong:
    alphabet = alphabet + 1
    print alphabet
    if ldata[alphabet] == "a":
        print "a" 
    elif ldata[alphabet] == "b":
        print "b"
    elif ldata[alphabet] == "c":
        print "c"
    elif ldata[alphabet] == "d":
        print "d"
    elif ldata[alphabet] == "e":
        print "e"
    elif ldata[alphabet] == "f":
        print "f"
    elif ldata[alphabet] == "g":
        print "g"
    elif ldata[alphabet] == "h":
        print "h"
    elif ldata[alphabet] == "i":
        print "i"
    elif ldata[alphabet] == "j":
        print "j"
    elif ldata[alphabet] == "k":
        print "k"
    elif ldata[alphabet] == "l":
        print "l"
    elif ldata[alphabet] == "m":
        print "m"
    elif ldata[alphabet] == "n":
        print "n"
    elif ldata[alphabet] == "o":
        print "o"
    elif ldata[alphabet] == "p":
        print "p"
    elif ldata[alphabet] == "q":
        print "q"
    elif ldata[alphabet] == "r":
        print "r"
    elif ldata[alphabet] == "s":
        print "s"
    elif ldata[alphabet] == "t":
        print "t"
    elif ldata[alphabet] == "u":
        print "u"
    elif ldata[alphabet] == "v":
        print "v"
    elif ldata[alphabet] == "w":
        print "w"
    elif ldata[alphabet] == "x":
        print "x"
    elif ldata[alphabet] == "y":
        print "y"
    elif ldata[alphabet] == "z":
        print "z"
    else:
        #deletes non letter and all of the same things from the list
        z = ldata[alphabet]
        ldata = [x for x in ldata if x != z]

它达到57742元素，然后列表索引超出范围。我计算了清单，它超越了它。这也不是pythons列表中最大可能的元素数量。我很困惑，想知道是否有任何我可能错过的东西。请在星期一帮助这个:(。如果有更简单的方法可以做到这一点，我会非常感谢。

Answer 1

<强>更新

错误来自于您在迭代时从列表中删除的事实。纠正这种情况的最佳方法如下：

new_list = [char for char in ldata if "a" <= char <= "z"]

每次删除项目时，都可以通过递减howlong来更正此方法。 您可以执行以下操作，这应该避免列表索引超出范围问题：

for char in ldata:
    if "a" <= char <= "z": 
        print(char)

通过使用for-each样式循环，您将遍历列表中的每个条目。这将确保您到达每个项目，而不会使您的索引超出范围。

完全赞同@ DYZ建议使用if "a" <= ldata[alphabet] <= "z": print(ldata[alphabet])作为for循环的内部部分！

当剩下更多元素时，我会继续让列表索引超出范围，我该如何解决这个问题？

1 个答案: