Python - 拆分函數 - 列表索引超出范圍

Question

我正在嘗試在for循環中獲取子字符串。 為此，我使用這個：

for peoject in subjects:
        peoject_name = peoject.content
        print(peoject_name, " : ", len(peoject_name), " : ",  len(peoject_name.split('-')[1]))

我有一些項目在句子中沒有任何“ - ”。 我怎么處理這個？

我遇到了這個問題：

builtins.IndexError: list index out of range

Answer 1

for peoject in subjects:
    try:
        peoject_name = peoject.content
        print(peoject_name, " : ", len(peoject_name), " : ", len(peoject_name.split('-')[1]))
    except IndexError:
        print("this line doesn't have a -")

Answer 2

您有幾個選項，具體取決於您在沒有連字符的情況下要執行的操作。

通過[-1]從拆分中選擇最后一項，或使用三元語句來應用替代邏輯。

x = 'hello-test'
print(x.split('-')[1])   # test
print(x.split('-')[-1])  # test

y = 'hello'
print(y.split('-')[-1])                                 # hello
print(y.split('-')[1] if len(y.split('-'))>=2 else y)   # hello
print(y.split('-')[1] if len(y.split('-'))>=2 else '')  # [empty string]

Answer 3

你可以檢查peoject_name是否有'-' ：

for peoject in subjects:
        peoject_name = peoject.content
        if '-' in peoject_name:
            print(peoject_name, " : ", len(peoject_name), " : ",  
                  len(peoject_name.split('-')[1]))
        else:
            # something else