Question

我有多个csv文件，我想将它们组合成一个df。

它们都是这种通用格式，有两个索引列：

                                           1     2
CU0112-005287-7 Output Energy, (Wh/h)   0.064   0.066
CU0112-005287-7 Lights (Wh)                0     0

                                            1     2
CU0112-001885-L Output Energy, (Wh/h)   1.33    1.317
CU0112-001885-L Lights (Wh)             1.33    1.317

依旧......

合并的df将是：

                                           1     2
CU0112-005287-7 Output Energy, (Wh/h)   0.064   0.066
CU0112-005287-7 Lights (Wh)                0     0
CU0112-001885-L Output Energy, (Wh/h)   1.33    1.317
CU0112-001885-L Lights (Wh)             1.33    1.317

我正在尝试这段代码：

import os
import pandas as pd
import glob

files = glob.glob(r'2017-12-05\Aggregated\*.csv')   //folder which contains all the csv files

df = pd.merge([pd.read_csv(f, index_col=[0,1])for f in files], how='outer')

df.to_csv(r'\merged.csv')

但是我收到了这个错误：

TypeError: merge() takes at least 2 arguments (2 given)

Answer 1

我认为您需要concat而不是merge：

df = pd.concat([pd.read_csv(f, index_col=[0,1]) for f in files])

Answer 2

您可以尝试以下操作。我对DataFrame结合逻辑

做了一些更改

import os
import pandas as pd
import glob

files = glob.glob(r'2017-12-05\Aggregated\*.csv')   //folder which contains all the csv files

df = reduce(lambda df1,df2: pd.merge(df1,df2,on='id',how='outer'),[pd.read_csv(f, index_col=[0,1])for f in files] )

df.to_csv(r'\merged.csv')

Answer 3

一种简单的方法：

创建名称为csvs的列表：

files=listdir()
csvs=list()
for file in files:
    if file.endswith(".csv"):
        csvs.append(file)

连接csvs：

data=pd.DataFrame()
for i in csvs:
    table=pd.read_csv(i)
    data=pd.concat([data,table])

Pandas结合了多个csv文件

3 个答案: