在python中删除列表中的年份起始日期

Question

我想把这个数组中的日期改成/15。数组是['6/03/15'，'9/03/15'，'10/03/15'，'11/03/15'，'12/03/15'，'13/03/15'，'16/03/15'，'17/03/15'，'18/03/15'，'19/03/15']，命名为dateList。你知道吗

def changeDateLength(dateList):
    dateLength = dateList[0]  
    newList = []

    for date in dateList:
       if len(dateLength[0]) > 7:
          shortDateLength = dateLength[:5]
       else:
          shortDateLength = dateLength[:4]
       newList.append(shore)
    return newList

列表打印为['6/03'、'6/03'、'6/03'、'6/03'、'6/03'、'6/03'、'6/03'、'6/03'、'6/03']

Answer 1

因为您使用的是日期，所以可以使用time模块对其进行解析和格式化。你知道吗

import time

def strip_year(date):
    return time.strftime('%-m/%d', time.strptime(date, '%d/%m/%y'))

Answer 2

列表理解：

迭代给定列表中的每个元素，按/拆分元素，然后再按/将拆分结果的前两项连接起来

>>> l
['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
>>> ["/".join(i.split("/")[:2]) for i in l ]
['6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']

---

关于您的代码：

您的代码：

def changeDateLength(dateList):
    #- Why first item from the list is consider? This will raise exception IndexError
    # when input is empty list.
    # So not need to this.
    dateLength = dateList[0]

    #- Yes correct need new list varable. 
    newList = []

    for date in dateList:
        #- We iterate item from the list.
        # so do process on item . dateLength[0] means first character from the dateLength variable which length is always 1.
        # 1 > 7 will return False.
        if len(dateLength[0]) > 7:
            shortDateLength = dateLength[:5]
        else:
            shortDateLength = dateLength[:4]

        #= Raise NameError exception because shore is not define
        newList.append(shore)   

    return newList

尝试：

def changeDateLength(dateList):
    newList = []
    for date_item in dateList:
        if len(date_item) > 7:
            shortDateLength = date_item[:5]
        else:
            shortDateLength = date_item[:4]
        newList.append(shortDateLength)

    return newList


dateList =  ['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
new_dateList = changeDateLength(dateList)
print "new_dateList:", new_dateList

Answer 3

尝试以下简单的列表理解，我们按'/'拆分，将所有项都放到最后一项，并用'/'连接：

def changeDateLength(datelist):
    return ['/'.join(item.split('/')[:-1]) for item in datelist]

---

>>> dateList = ['6/03/15', '9/03/15', '10/03/15', '11/03/15', '12/03/15', '13/03/15', '16/03/15', '17/03/15', '18/03/15', '19/03/15']
>>> changeDateLength(dateList)
['6/03', '9/03', '10/03', '11/03', '12/03', '13/03', '16/03', '17/03', '18/03', '19/03']
>>>