Question

有一个这样的列表（只有更大）称为＆＃39; data_list＆＃39;：

2017-04-01, available
2017-04-02, available
2017-04-01, available
2017-04-02, available
2017-04-02, available
2017-04-01, available
2017-04-02, available
2017-04-01, available
2017-04-02, available
2017-04-01, available
etcetera

我使用了以下代码，

dates = collections.defaultdict(list)
for date, xyz in data_list:
    dates[date].append(xyz)
counts = {date: collections.Counter(xyz) for date, xyz in dates.items()}

要创建这样的字典：

2017-04-01,Counter({'available': 9})
2017-04-02,Counter({'available': 12})
2017-04-03,Counter({'available': 9})
2017-04-04,Counter({'available': 4})
2017-04-05,Counter({'available': 9})
2017-04-06,Counter({'available': 2})

我将如何继续删除＆＃34; Counter＆＃34;？（最终是像＆＃39;（＆＃39;和＆＃39; {＆＃39;）

这样的字符

目前，我有这段代码。但它没有做任何事情。

for x in my_dictionary:
try:
    x = x.replace('Counter','')
except:
    pass

最终的主要目标是获得这样的.csv文件：

date, available
2017-04-01, 9
2017-04-02, 12
2017-04-03, 9
2017-04-04, 4
2017-04-05, 9
2017-04-06, 2

字典的部分打印输出：

'2018-12-12': Counter({'available': 3}), '2018-04-28': Counter({'available': 4}), '2017-12-16': Counter({'available': 2}), '2017-12-17': Counter({'available': 2}), '2017-12-14': Counter({'available': 2}), '2017-12-15': Counter({'available': 2}), '2017-12-12': Counter({'available': 2}), '2017-12-13': Counter({'available': 2}), '2017-12-10': Counter({'available': 2}), '2017-12-11': Counter({'available': 2}), '2017-12-18': Counter({'available': 2}), '2017-12-19': Counter({'available': 2}), '2018-05-31': Counter({'available': 4}), '2018-05-30': Counter({'available': 4}),

Answer 1

在这种情况下，您根本不需要collections.Counter，即使使用collections.defaultdict也可以取消。这样就可以了：

dates = {}
for date, value in data_list:
    if value == "available":
        dates[date] = dates.get(date, 0) + 1
# dates contains (date, count) pairs

也应该快得多。然后，您可以使用csv.writer或csv.DictWriter（根据所需的输出CSV）写出最终的CSV。例如：

import csv

data_list = [['2017-04-01', 'available'],
             ['2017-04-02', 'available'],
             ['2017-04-01', 'available'],
             ['2017-04-02', 'available'],
             ['2017-04-02', 'available'],
             ['2017-04-01', 'available'],
             ['2017-04-02', 'available'],
             ['2017-04-01', 'available'],
             ['2017-04-02', 'available'],
             ['2017-04-01', 'available']]

dates = {}
for date, value in data_list:
    if value == "available":
        dates[date] = dates.get(date, 0) + 1

with open("output.csv", "wb") as f:  # open output.csv for writing
    writer = csv.writer(f)  # create a csv.writer
    writer.writerow(("date", "available"))  # write our header
    for row in dates.iteritems():  # sorted(dates.iteritems()) instead for date-sorted output
        writer.writerow(row)  # write the row

为您提供有效的CSV格式：

date,available
2017-04-02,5
2017-04-01,5

您可以在几乎任何电子表格应用中打开它。如果您希望将其格式化为输出，请注意这不是有效的CSV。

更新 - 每个日期都有多个可用值的版本（此时使用collections.Counter变得更方便，但要与主题保持一致）：

import csv

data_list = [['2017-04-01', 'available'],
             ['2017-04-02', 'available'],
             ['2017-04-01', 'booked'],
             ['2017-04-02', 'available'],
             ['2017-04-02', 'booked'],
             ['2017-04-01', 'available'],
             ['2017-04-02', 'blocked'],
             ['2017-04-01', 'blocked'],
             ['2017-04-02', 'blocked'],
             ['2017-04-01', 'available']]

dates = {}
values = set()  # just so we know what are possible values for the latter CSV header
for date, value in data_list:
    values.add(value)
    dates.setdefault(date, {})[value] = dates.get(date, {}).get(value, 0) + 1

with open("output.csv", "wb") as f:  # open output.csv for writing
    header = ["date"] + list(values)  # set header to date,<available_values>
    writer = csv.DictWriter(f, header)
    writer.writeheader()
    for k, v in dates.iteritems():  # sorted(dates.iteritems()) instead for date-sorted output
        v.update({"date": k})  # add the date to our row
        writer.writerow(v)  # write the row

将output.csv创建为：

date,available,booked,blocked
2017-04-02,2,1,2
2017-04-01,3,1,1

您可以拥有尽可能多的价值＆＃39;你想要的字段，所以它不必只有3个。

Answer 2

你快到了。您可以使用available键从计数器获取可用计数，如下所示：

counts = {date: collections.Counter(xyz)['available'] for date, xyz in dates.items()}


import csv

def to_row(date, counter):
     return date, counter['booked'], counter['blocked'], counter['available']

counts = [to_row(date, collections.Counter(xyz)) for date, xyz in dates.items()]

 writer = csv.writer(open('<filename>.csv', 'w'))
 writer.writerows(counts)

从字典中删除特定的文本和字符

2 个答案: