python 将 csv 文件读取为字典并排序和递增计数器

Question

我希望有人能给我指出正确的方向。从我读过的内容来看，我相信使用字典最适合这种需要，但我绝不是一个高级程序员，我希望有人能提供一些帮助并帮助我。这是我的 CSV 文件:

11362672,091914,100914,100.00,ITEM,11,N,U08
12093169,092214,101514,25.00,ITEM,11,N,U10
12162432,091214,101214,175.00,ITEM,11,N,U07
11362672,091914,100914,65.00,ITEM,11,N,U08
11362672,091914,100914,230.00,ITEM,11,N,U08

我想将第一列作为键，以下列作为该键的值，以便:

1. 按键排序数据
2. 反击事件
3. 附加计数器

这是我想要获得的输出:

1,11362672,091914,100914,100.00,ITEM,11,N,U08 # occurrence 1 for key: 11362672
2,11362672,091914,100914,65.00,ITEM,11,N,U08 # occurrence 2 for key: 11362672
3,11362672,091914,100914,230.00,ITEM,11,N,U08 # occurrence 3 for key: 11362672
1,12093169,092214,101514,25.00,ITEM,11,N,U10 # occurrence 1 for key: 12093169
1,12162432,091214,101214,175.00,ITEM,11,N,U07 # occurrence 1 for key: 12162432

我需要保持每一行的完整性，这就是我认为字典最有效的原因。我没有太多，但这就是我的开始。这是我需要帮助来排序、计数和追加计数器的地方。

import csv
with open('C:/Download/item_report1.csv', 'rb') as infile:
     reader = csv.reader(infile)
     dict1 = {row[0]:row[1:7] for row in reader}
     print dict1

给我:

{
'11362672': ['091914', '100914', '230.00', 'ITEM', '11', 'N'], 
'12093169': ['092214', '101514', '25.00', 'ITEM', '11', 'N'], 
'12162432': ['091214', '101214', '175.00', 'ITEM', '11', 'N']
}

Answer 1

简而言之，您应该使用一个计数器来计算键和一个列表来存储行。

当您在 csv 中阅读时，记录您看到键值的次数，并在阅读时将其插入每一行的开头。

读入文件后，您可以先按键值排序，然后按出现次数计数器排序。

import csv

counter = {}
data = []

with open('report.csv','rb') as infile:
  for row in csv.reader(infile):
    key = row[0]
    if key not in counter:
      counter[key] = 1
    else:
      counter[key] += 1
    row.insert(0,counter[key])
    data.append(row)

for row in sorted(data,key=lambda x: (x[1],x[0])):
  print row

这里又是同样的东西，写法略有不同，根据官方风格指南有 4 个空格，而不是我个人偏好的两个空格。

import csv

# key function for sorting later
def second_and_first(x):
    return (x[1],x[0])

# dictionary to store key_fields and their counts
counter = {}
# list to store rows from the csv file
data = []

with open('report.csv','rb') as infile:
    for row in csv.reader(infile):
        # For convenience, assign the value of row[0] to key_field
        key_field = row[0]
        # if key_field is not in the dictionary counter. Add it with a value of 1
        if key_field not in counter:
            counter[key_field] = 1
        # otherwise, it is there, increment the value by one.
        else:
            counter[key_field] += 1
        # insert the value associated with key_field in the counter into the start of
        # the row
        row.insert(0,counter[key_field])
        # Append the row to 
        data.append(row)

for row in sorted(data,key=second_and_first):
    print row