將python文件中的數據分組時，將CSV文件中的一列拆分為多列（無熊貓）

Question

我目前正在學習Python，並希望就我的問題之一尋求幫助。 我有一個 ”;” 分隔的文件（如下所示），我正在嘗試刷出並提取excel和csv格式的一些數據。

我的原始CSV文件。

    COUNTRY  COUNTRY_TIME            COUNTRY_REF        PRODUCT
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221     APPLE%BOX%LYON%022018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221     APPLE%BOX%LYON%032018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221     APPLE%BOX%LYON%052018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221     APPLE%BOX%LYON%062018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221     APPLE%BOX%NICE%032018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221    APPLE%BOX%LILLE%022018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221    APPLE%BOX%NEM%022018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221    APPLE%COVER%CWF%022018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221   APPLE%COVER%FZF%022018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221   APPLE%COVER%MX1%022018
    FRANCE  FRANCE20180222.16.30.00  FRANCE20180221 APPLE%BIGBOX%DIJON%022018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%BODEN%012019
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%BODEN%022019
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%BODEN%032018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%BODEN%042018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%BODEN%052018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%BODEN%062018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%FLEN%012019
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%FLEN%032018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%FLEN%042018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%FLEN%052018
    SWEDEN  SWEDEN20180223.02.11.00  SWEDEN20180222 APPLE%SMALLBOX%FLEN%062018

我最終的預期數據應該是

COUNTRY EXCHANGE_CODE   TOWN_CODE   MONTH_CODE
FRANCE  BOX              LYON       022018;032018;052018;062018
FRANCE  BOX              NICE       032018
FRANCE  BOX              LILLE      022018
FRANCE  BOX              NEM        022018
FRANCE  COVER            CWF        022018
FRANCE  COVER            FZF        022018
FRANCE  COVER            MX1        022018
FRANCE  BIGBOX           DIJON      022018
SWEDEN  SMALLBOX         BODEN      012019;022019;032018;042018;052018;062018
SWEDEN  SMALLBOX         FLEN       012019;032018;042018;052018;062018

我創建了下面的腳本，但只能實現到下面的表。

import csv
import os
from collections import defaultdict, OrderedDict
import itertools
from operator import itemgetter

in_path = os.path.expanduser("~/Desktop/FUTURES.csv")
out_path = os.path.expanduser("~/Desktop/Finalresult.csv")

with open(in_path, 'r') as f_in, open(out_path, 'w', newline='') as f_out:
    csv_reader = csv.reader(f_in, delimiter=';')
    writer = csv.writer(f_out)

    all = []
    row = next(csv_reader)
    row.append('LFU')
    row.append('EXCHANGE_CODE')
    row.append('TOWN_CODE')
    row.append('MONTH_CODE')
    all.append(row)

    for row in csv_reader:
        if row[0] in ['FRANCE', 'SWEDEN']:

            row.append(row[3].split('%')[0])
            row.append(row[3].split('%')[1])
            row.append(row[3].split('%')[2])
            row.append(row[3].split('%')[3])
            all.append(row)

    writer.writerows(map(itemgetter(0, 5, 6, 7), all))

我目前的結果

COUNTRY FRUIT   EXCHANGE_CODE   TOWN_CODE   MONTH_CODE
FRANCE  APPLE   BOX                 LYON    022018
FRANCE  APPLE   BOX                 LYON    032018
FRANCE  APPLE   BOX                 LYON    052018
FRANCE  APPLE   BOX                 LYON    062018
FRANCE  APPLE   BOX                 NICE    032018
FRANCE  APPLE   BOX                 LILLE   022018
FRANCE  APPLE   BOX                 NEM     022018
FRANCE  APPLE   COVER               CWF     022018
FRANCE  APPLE   COVER               FZF     022018
FRANCE  APPLE   COVER               MX1     022018
FRANCE  APPLE   BIGBOX              DIJON   022018
SWEDEN  APPLE   SMALLBOX            BODEN   012019
SWEDEN  APPLE   SMALLBOX            BODEN   022019
SWEDEN  APPLE   SMALLBOX            BODEN   032018
SWEDEN  APPLE   SMALLBOX            BODEN   042018
SWEDEN  APPLE   SMALLBOX            BODEN   052018
SWEDEN  APPLE   SMALLBOX            BODEN   062018
SWEDEN  APPLE   SMALLBOX            FLEN    012019
SWEDEN  APPLE   SMALLBOX            FLEN    032018
SWEDEN  APPLE   SMALLBOX            FLEN    042018
SWEDEN  APPLE   SMALLBOX            FLEN    052018
SWEDEN  APPLE   SMALLBOX            FLEN    062018

我將非常感謝我能提供的任何幫助。

PS-我不想使用Numpy的Pandas。

Answer 1

如果要忽略所有庫，這是不導入的解決方案：

with open('smntg.csv') as fin, open('smntg_else.csv', 'w') as fout:
    header = ['COUNTRY', 'EXCHANGE_CODE', 'TOWN_CODE', 'MONTH_CODE']
    data = fin.readlines()
    needed = list(map(str.strip, data))[1:]   
    dealtWith = []
    for line in needed:
        apart = line.split(';')
        country = apart[0]
        exchange, town, month = apart[-1].split('%')[1:]
        dealtWith.append([country, exchange, town, month])        
    packed = {tuple(dealtWith[0][:3]): [dealtWith[0][3]]}
    for item in dealtWith[1:]:
        key = tuple(item[:3])
        value = item[3]
        if key in packed:
            packed[key].append(value)
        else:
            packed[key] = [value]
    joined = {k: ';'.join(v) for k, v in packed.items()}
    finalized = [list(i) + [j] for i, j in joined.items()]
    finalized.sort()
    commaDelimited = [','.join(fline) + '\n' for fline in finalized]
    fout.write(','.join(header) + '\n')
    fout.writelines(commaDelimited)

Answer 2

您不能為每條讀取線寫一行，因為一條輸出線可以由許多輸入線組成。 但是，如果您可以假設輸入文件是按照COUNTRY，EXCHANGE_CODE和TOWN排序的，那么如果COUNTRY，EXCHANGE_CODE和TOWN相同，則只需在前一行的末尾添加新的月份即可。

您的代碼可能變為：

...
with open(in_path, 'r') as f_in, open(out_path, 'w', newline='') as f_out:
    csv_reader = csv.reader(f_in, delimiter=';')
    writer = csv.writer(f_out)

    all = []
    row = next(csv_reader)
    row.append('LFU')
    row.append('EXCHANGE_CODE')
    row.append('TOWN_CODE')
    row.append('MONTH_CODE')

    old = row                       # just remember it

    for row in csv_reader:
        if row[0] in ['FRANCE', 'SWEDEN']:

            row.append(row[3].split('%')[0])
            row.append(row[3].split('%')[1])
            row.append(row[3].split('%')[2])
            row.append(row[3].split('%')[3])
            if row[0] == old[0] and row[5] == old[5] and row[6] == old[6]:
                old[7] += ';' + row[7]
            else:
                all.append(old)                      # write down previous row
                old = row
    all.append(old)                                  # do not forget last row

    writer.writerows(map(itemgetter(0, 5, 6, 7), all))