加入多个文件字典

Question

我有一个包含一些字段的母版 table。我想将它与其他一堆 csvs 一起加入。

当前数据如下：

文件 1：

Key  Attrib1  Attrib2  Attrib3  Attrib4

文件 2：

Key Attrib5

文件 3：

Key Attrib6

我希望我的最终输出看起来像：

Key   Attrib1  Attrib2  Attrib3  Attrib4 Attrib5 Attrib6, etc.

并非所有文件都包含所有密钥。

当前代码：

master = "in.csv"
file1 = "file.csv"
file2 = "file2.csv"
prime = list()
D1 = {}

with open(master) as f:
    for k in csv.reader(f):
        prime.append(k[0])

for k in prime:
    with open(file1,'r') as csvfile:
        rd = csv.reader(csvfile,delimiter=",")
        for row in rd:
            if row[0] ==k:
                D1 = dict((row[0],row[1]) for rows in rd)
    with open(file2,'r') as csvfile:
        rd = csv.reader(csvfile,delimiter=",")
        for row in rd:
            if row[0] ==k:
                D1 = D1+dict((row[0],row[1]) for rows in rd)

Answer 1

这里的想法是打开所有三个文件并将它们写入一个新的.csv 文件。我将如何加入 csv 文件的一般想法是这样的：

import glob
import csv

# gets all the files in your dictionary that end with .csv
csv_files = glob.glob('*.csv')

        # create the new csv file, which will be your output
        with open('filename.csv', 'w') as outfile:
                writer = csv.writer(outfile, delimiter = ',')

                for csv_file in csv_files:
                    with open(csv_file) as infile:
                        reader = csv.reader(infile, delimiter = ',')
                        for row in reader:
                            writer.writerow(row)

您必须操纵 "row" 的确切组成，使其与您的数据的工作方式相匹配（在没有您需要的列的数据上创建空列）。

可能的解决方案是为每个文件创建一个元组格式，在其中为您需要的位置创建空位置。将元组写入行将像这样工作。

for row in reader:

    if csv_file == 'file1':
        # '' represents a blank field in column
        data_to_write = (row[0], row[1], '', row[2])

    elif csv_file == 'file2':
        data_to_write = '', row[0], row[1],row[2]

    writer.writerow(data_to_write)

Answer 2

如果不是您想要的，我认为这确实会关闭：

master = "in.csv"
filelist = "file.csv", "file2.csv"
joined = "joined.csv"
dict1 = {}

with open(master, 'r') as csvfile:
    for row in csv.reader(csvfile):
        key = row[0]
        dict1[key] = row[1:]  # note this does not check for duplicate keys

for filename in filelist:
    with open(filename, 'rb') as csvfile:
        seen = set()
        for row in csv.reader(csvfile):
            key = row[0]
            if key in dict1:
                if key in seen:
                    print('Error: duplicate key %r in file %r - ignored' %
                                   (key, filename))
                else:
                    dict1[key].append(row[1])
                    seen.add(key)
            else:  # key not in master
                pass  # ignore    

        # add null entry for any keys not present in this file
        for key in dict1:
            if key not in seen:
                dict1[key].append(None)

# write the data in the merged dictionary into a new csv file
with open(joined, 'wb') as newcsvfile:
    csv.writer(newcsvfile).writerows(
        ([key]+attrlist) for key, attrlist in sorted(dict1.iteritems()))

加入多个文件字典

Join Multiple Files Dictionary

python

csv

merge

join

python-2.5