使用 Python 进行分组和复选标记

Question

我有几个文件，每个文件都有这样的数据（文件名：里面的数据由换行符分隔）：

1. 迈克：飞机\n汽车
2. Paula：飞机\n火车\n船\n汽车
3. 比尔：船\n火车
4. 斯科特：汽车

如何使用 python 创建一个 csv 文件，将所有不同的车辆分组，然后将 X 放在适用的人身上，例如：

Answer 1

以下是如何解析此类文件的示例。

注意这里的字典是无序的。您可以使用标准库中的有序字典（在 Python 3.2 / 2.7 的情况下），如果您有较旧的 Python 版本或只是将订单保存在附加列表中，请查找任何可用的实现/反向移植 :)

data = {}
name = None

with open(file_path) as f:
    for line in f:
        if ':' in line: # we have a name here
            name, first_vehicle = line.split(':')
            data[name] = set([first_vehicle, ])  # a set of vehicles per name
        else:
            if name:
                data[name].add(line)

# now a dictionary with names/vehicles is available
# let's convert it to simple csv-formatted string..

# a set of all available vehicles
vehicles = set(v for vlist in data.values()
               for v in vlist)

for name in data:
    name_vehicles = data[name]
    csv_vehicles = ''
    for v in vehicles:
        if v in name_vehicles:
            csv_vehicles += v
        csv_vehicles += ','

    csv_line = name + ',' + csv_vehicles

Answer 2

假设输入如下所示：

Mike: Plane
Car
Paula: Plane
Train
Boat
Car
Bill: Boat
Train
Scott: Car

这个 python 脚本将车辆放在字典中，由人索引：

#!/usr/bin/python

persons={}
vehicles=set()

with open('input') as fd:
    for line in fd:
        line = line.strip()
        if ':' in line:
            tmp = line.split(':')
            p = tmp[0].strip()
            v = tmp[1].strip()
            persons[p]=[v]
            vehicles.add(v)
        else:
            persons[p].append(line)
            vehicles.add(line)

for k,v in persons.iteritems():
    print k,v

print 'vehicles', vehicles

结果：

Mike ['Plane', 'Car']
Bill ['Boat', 'Train']
Scott ['Car']
Paula ['Plane', 'Train', 'Boat', 'Car']
vehicles set(['Train', 'Car', 'Plane', 'Boat'])

现在，所有需要的数据都放在数据结构中。 csv 部分留给读者作为练习:-)

Answer 3

假设这些行号不存在（如果存在则很容易修复），并且输入文件如下：

Mike: Plane
Car
Paula: Plane
Train
Boat
Car
Bill: Boat
Train
Scott: Car

可以在这里找到解决方案：https://gist.github.com/999481

import sys
from collections import defaultdict
import csv

# see http://stackoverflow.com/questions/6180609/group-and-check-mark-using-python
def main():
    # files = ["group.txt"]
    files = sys.argv[1:]
    if len(files) < 1:
        print "usage: ./python_checkmark.py file1 [file2 ... filen]"

    name_map = defaultdict(set)

    for f in files:
        file_handle = open(f, "r")
        process_file(file_handle, name_map)
        file_handle.close()

    print_csv(sys.stdout, name_map) 

def process_file(input_file, name_map):
    cur_name = ""
    for line in input_file:
        if ":" in line:
            cur_name, item = [x.strip() for x in line.split(":")]
        else:
            item = line.strip()
        name_map[cur_name].add(item)


def print_csv(output_file, name_map):
    names = name_map.keys()
    items = set([])
    for item_set in name_map.values():
        items = items.union(item_set)

    writer = csv.writer(output_file, quoting=csv.QUOTE_MINIMAL)
    writer.writerow( [""] + names )
    for item in sorted(items):
        row_contents = map(lambda name:"X" if item in name_map[name] else "", names)
        row = [item] + row_contents
        writer.writerow( row )


if __name__ == '__main__':
    main()

输出：

,Mike,Bill,Scott,Paula 
Boat,,X,,X 
Car,X,,X,X 
Plane,X,,,X 
Train,,X,,X 

这个脚本唯一不做的就是按照名称所在的顺序保留列。可以保留一个单独的列表来维护顺序，因为地图/字典本质上是无序的。

Answer 4

最优雅和最简单的方法是这样的：

vehiclesToPeople = {}
people = []

for root,dirs,files in os.walk('/path/to/folder/with/files'):
    for file in files:
        person = file
        people += [person]
        path = os.path.join(root, file)

        with open(path) as f:
            for vehicle in f:
                vehiclesToPeople.setdefault(vehicle,set()).add(person)

people.sort()
table = [ ['']+people ]
for vehicle,owners in peopleToVehicles.items():
    table.append([('X' if p in vehiclesToPeople[vehicle] else '') for p in people])

csv = '\n'.join(','.join(row) for row in table)

你也可以pprint.pprint(table)看看。