Question

我想在一个if语句中使用迭代的＆＃39; i＆＃39; in for循环for dataframe但它显示执行错误。我的代码是 -

import pandas as pd

data = pd.read_csv("C:\\Users\\Abhi\\Desktop\\Book1.csv",low_memory=False)

data['DV+']=pd.Series("",index=data.index)

for j in range(len(data.index)):

    if (data['Customer_Site_ID'][j]==data['Customer_Site_ID'][j+1] and (data['DCVolt'][j]-data['DCVolt'][j+1])>0.2 and min(data['BatDC'][j],data['BatDC'][j+1])>0 and (data['BatDC'][j]-data['BatDC'][j+1])<5):
        data['DV+'][j]=1
    else:
        data['DV+'][j]=0
data.to_csv("C:\\Users\\Abhi\\Desktop\\book11.csv", index=False,encoding='utf-8')

我得到的错误是 -

Traceback (most recent call last):

  File "<ipython-input-1-0469458ba48f>", line 1, in <module>
    runfile('C:/Users/Abhi/Desktop/newfeed.py', wdir='C:/Users/Abhi/Desktop')

  File "C:\Users\Abhi\Anaconda3\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 714, in runfile
    execfile(filename, namespace)

  File "C:\Users\Abhi\Anaconda3\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 89, in execfile
    exec(compile(f.read(), filename, 'exec'), namespace)

  File "C:/Users/Abhi/Desktop/newfeed.py", line 15, in <module>
    if (data['Customer_Site_ID'][j]==data['Customer_Site_ID'][j+1] and (data['DCVolt'][j]-data['DCVolt'][j+1])>0.2 and min(data['BatDC'][j],data['BatDC'][j+1])>0 and (data['BatDC'][j]-data['BatDC'][j+1])<5):

  File "C:\Users\Abhi\Anaconda3\lib\site-packages\pandas\core\series.py", line 603, in __getitem__
    result = self.index.get_value(self, key)

  File "C:\Users\Abhi\Anaconda3\lib\site-packages\pandas\indexes\base.py", line 2169, in get_value
    tz=getattr(series.dtype, 'tz', None))

  File "pandas\index.pyx", line 98, in pandas.index.IndexEngine.get_value (pandas\index.c:3557)

  File "pandas\index.pyx", line 106, in pandas.index.IndexEngine.get_value (pandas\index.c:3240)

  File "pandas\index.pyx", line 154, in pandas.index.IndexEngine.get_loc (pandas\index.c:4279)

  File "pandas\src\hashtable_class_helper.pxi", line 404, in pandas.hashtable.Int64HashTable.get_item (pandas\hashtable.c:8564)

  File "pandas\src\hashtable_class_helper.pxi", line 410, in pandas.hashtable.Int64HashTable.get_item (pandas\hashtable.c:8508)

KeyError: 15

请告诉我使用for（any）循环中的迭代元素访问数据框中行的值的正确方法。

Answer 1

我会推荐pandas（0.20.1）文档，特别是关于索引和选择数据的this部分。

您可以使用.loc以及其他选项访问数据框中的行值。

>>> data = pd.DataFrame({'column':[i for i in range(15)]})

>>> for i in range(len(data)):
...     print(data.loc[i, 'column'])
... 
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14

使用迭代元素时if语句中的错误

1 个答案: