相关疑难解决方法(0)

以下是我的数据框

import pandas as pd
df = pd.DataFrame({'name': ['jon','sam','jane','bob'],
           'age': [30,25,18,26],
           'sex':['male','male','female','male']})


   age  name     sex
0   30   jon    male
1   25   sam    male
2   18  jane  female
3   26   bob    male

我想在第一个位置插入一个新行

姓名:院长,年龄:45岁,性别:男

   age  name     sex
0   45  dean    male
1   30   jon    male
2   25   sam    male
3   18  jane  female
4   26   bob    male

在熊猫中做到这一点的最佳方法是什么？

I want to process stock level-2 data in pandas. Suppose there are four kinds data in each row for simplicity:

• millis: timestamp, int64
• last_price: the last trade price, float64,
• ask_queue: the volume of ask side, a fixed size (200) array of int32
• bid_queue: the volume of bid side, a fixed size (200) array of int32

Which can be easily defined as a structured dtype in numpy:

dtype = np.dtype([
   ('millis', 'int64'), 
   ('last_price', 'float64'), 
   ('ask_queue', ('int32', 200)), 
   ('bid_queue', ('int32', 200))
]) …