Python pandas 数据帧读取from_records，“AssertionError：1列传递，传递数据有22列” [英] Python pandas dataframe read from_records, "AssertionError: 1 columns passed, passed data had 22 columns"

问题描述

我有一个列表，其中 a 的长度为 806 。我想导入到数据框，列表中的第一个项目是列名。我的代码是：

I have a list where a is 806 in length. I want to import to a dataframe where the first item in the list is the column name. My code is:

import pandas as pd
b = pd.DataFrame.from_records(a[1:],columns=[a[0]])

这给我一个错误 AssertionError ：1列通过，传递数据有22列，而显然我只有一列。

this gives me an error of AssertionError: 1 columns passed, passed data had 22 columns while clearly i have only one column.

我已经尝试了代码的表示，有用。所以我不知道这里发生了什么。这是代码的代码：

I've tried a representation of the code and it works. So I'm not sure what is going on here. Here is a representation of the code:

import pandas as pd
arr= ['title', 'a','b','','','']
arr= filter(None, arr)
b = pd.DataFrame.from_records(arr[1:],columns=[arr[0]] )

我的列表必须出错？我打印出 a ，它看起来很好，像一个常规列表。我已经粘贴了 a 的打印输出，并将其作为变量列表，并给出了相同的错误 AssertionError：传递1列，传递数据有22列。看起来像我的名单有问题。还有什么可以调试？

Must be something wrong with my list? I printed out a and it looks fine, like a regular list. I have pasted the printed output of a and placed that as the variable list, and it gives me the same error AssertionError: 1 columns passed, passed data had 22 columns. Seems like something wrong with my list. What else can I do to debug?

编辑（根据DSM建议）：

Edit (based on DSM suggestion):

import pandas as pd
arr=['Title', '000660.ks']
b = pd.DataFrame.from_records(arr[1:],columns=[arr[0]] )

这给了 AssertionError：1列传递，传递数据有8列

推荐答案

而不是使用 from_records 想要使用默认的DataFrame构造函数。

Instead of using from_records you want to use the default DataFrame constructor.

from_records 期望一些可重复的东西的列表，例如，字符串'0006660正在以（'0'，'0'，...，''）的形式读入.ks'在数据中收到有关8列的错误。

from_records expects a list of something iterable, so for example, the string '0006660.ks' is being read in as ('0','0',... ,'s') which is why you are getting an error about 8 columns in the data.

b = pd.DataFrame(a[1:], columns=[a[0]])

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