Python List拆分,按日期排序,然后加入

Python List splitting, sorting by date, then joining

好吧,我已经在这里待了好几个小时了,我承认失败,请求你的宽恕。

目标:我有多个文件(银行对账单下载),我想合并、排序、删除重复项。

下载的格式如下:

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"08/04/2015","Balance","5,804.30","Current Balance for account 123S14"
"08/04/2015","Balance","5,804.30","Available Balance for account 123S14"
"02/03/2015","241.25","Transaction description","2,620.09"
"02/03/2015","-155.49","Transaction description","2,464.60"
"03/03/2015","82.00","Transaction description","2,546.60"
"03/03/2015","243.25","Transaction description","2,789.85"
"03/03/2015","-334.81","Transaction description","2,339.12"
"04/03/2015","-25.05","Transaction description","2,314.07"

除了完全不知道我在做什么之外,我的主要问题之一是数值中包含逗号。我已经成功地编写了代码,去掉了这些"隐藏"的逗号,然后去掉了引号,这样我就有了一个csv…行。

所以我现在有了这种格式的数据

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['02/03/2015', ' \t ', '241.25\t ', ' \t ', 'Transaction Details
'
, '02/03/2015', ' \t ', ' \t ', '-155.49\t ', 'Transaction Details
'
, '03/03/2015', ' \t ', '82.00\t ', ' \t ', 'Transaction Details
'
, '03/03/2015', ' \t ', '243.25\t ', ' \t ', 'Transaction Details
'
, '02/03/2015', ' \t ', '241.25\t ', ' \t ', 'Transaction Details
'
]

我相信这使得它几乎可以对元素进行排序,但是我认为它现在是一个长列表,而不是一个列表。

我研究了排序并找到lambda…函数,所以我开始实现

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new_file_data = sorted(new_file_data, key=lambda item: item[0])

但元素[0]只是"在BOL上"。

我还注意到,我需要指示日期的格式可能不正确,这导致了我的这种构造:

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sorted(new_file_data, key=lambda d: datetime.strptime(d, '%d/%m/%Y'))

松散地说,我得到了"map"结构,但不知道如何组合,这样我就可以引用元素[0]以及如何引用它(datewise)。

现在我在这里,希望有人能把我推过这个障碍?我认为我需要更好地分割列表,这样每一行都是一个元素-我曾经得到过一个排序结果,但是所有的字段都是全局的,值(排序),日期,单词等等。

所以,如果有人能就我失败的列表操作以及如何构造这个排序lambda提供一些建议的话。

感谢那些有时间和知道如何回答这些初学者的问题的人。


如果我理解正确,您希望阅读csv的内容并按日期对其进行排序。

考虑到EDOCX1[0]的内容

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"08/04/2015","Balance","5,804.30","Current Balance for account 123S14"
"08/04/2015","Balance","5,804.30","Available Balance for account 123S14"
"02/03/2015","241.25","Transaction description","2,620.09"
"02/03/2015","-155.49","Transaction description","2,464.60"
"03/03/2015","82.00","Transaction description","2,546.60"
"03/03/2015","243.25","Transaction description","2,789.85"
"03/03/2015","-334.81","Transaction description","2,339.12"
"04/03/2015","-25.05","Transaction description","2,314.07"

我将使用csv模块读取数据。

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import csv
with open('data.csv') as f:
    data = [row for row in csv.reader(f)]

它给出:

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>>> data
[['08/04/2015', 'Balance', '5,804.30', 'Current Balance for account 123S14'],
 ['08/04/2015', 'Balance', '5,804.30', 'Available Balance for account 123S14'],
 ['02/03/2015', '241.25', 'Transaction description', '2,620.09'],
 ['02/03/2015', '-155.49', 'Transaction description', '2,464.60'],
 ['03/03/2015', '82.00', 'Transaction description', '2,546.60'],
 ['03/03/2015', '243.25', 'Transaction description', '2,789.85'],
 ['03/03/2015', '-334.81', 'Transaction description', '2,339.12'],
 ['04/03/2015', '-25.05', 'Transaction description', '2,314.07']]

然后,您可以使用datetime模块提供一个用于排序的键。

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import datetime
sorted_data = sorted(data, key=lambda row: datetime.datetime.strptime(row[0],"%d/%m/%Y"))

它给出:

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>>> sorted_data
[['02/03/2015', '241.25', 'Transaction description', '2,620.09'],
 ['02/03/2015', '-155.49', 'Transaction description', '2,464.60'],
 ['03/03/2015', '82.00', 'Transaction description', '2,546.60'],
 ['03/03/2015', '243.25', 'Transaction description', '2,789.85'],
 ['03/03/2015', '-334.81', 'Transaction description', '2,339.12'],
 ['04/03/2015', '-25.05', 'Transaction description', '2,314.07'],
 ['08/04/2015', 'Balance', '5,804.30', 'Current Balance for account 123S14'],
 ['08/04/2015', 'Balance', '5,804.30', 'Available Balance for account 123S14']]


您可以定义自己的排序功能。

把这两个问题混合起来,你就会得到你想要的(或接近的)东西:

自定义python列表排序

python日期字符串结束日期对象

在排序函数中,将日期从字符串转换为日期时间并进行比较

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def cmp_items(a, b):
    datetime_a = datetime.datetime.strptime(a.[0],"%d/%m/%Y").date()
    datetime_b = datetime.datetime.strptime(a.[0],"%d/%m/%Y").date()
    if datetime_a > datetime_b:
        return 1
    elif datetime_a == datetime_b:
        return 0
    else:
        return -1

然后,你只需要用它对列表进行排序

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new_file_data = new_file_data.sort(cmp_items)

之后仍然会有一些问题,具有相同日期的元素将以类似随机的顺序排列。您可以改进比较功能来比较更多的东西来防止这种情况发生。

顺便说一句,你还没有把被埋的逗号去掉,看起来你已经完全去掉了最后一部分。