pandas2: Pandas特有的数据类型Series和DataFrame

素颜马尾好姑娘i 2023-02-26 11:29 14阅读 0赞

Series和DataFrame是Pandas里最常用的基本数据类型：

## 1.创建Series ##

import pandas as pd

s1 = pd.Series([1,2,3,4,5])
    print(s1)

0    1
    1    2
    2    3
    3    4
    4    5
    dtype: int64

s2 = pd.Series([1,2,3.0,4,5])
    print(s2)

0    1.0
    1    2.0
    2    3.0
    3    4.0
    4    5.0
    dtype: float64

s3 = pd.Series([False, 1,2.0,'hello'])
    print(s3)

0    False
    1        1
    2        2
    3    hello
    dtype: object

### 改变第一列索引 ###

ss = pd.Series(['Bill','MicroSoft'],index=['person','company'])
    print(ss)

person          Bill
    company    MicroSoft
    dtype: object

## 2.创建DataFrame ##

import pandas as pd

print(persons)

Name    Occupation        Born        Died  age
    0  Rosaline Franklin       Chemist  1920-07-25  1958-04-16   37
    1     William Gosset  Statistician  1876-06-13  1937-10-16   61

persons.head()

<table> 
 <thead> 
  <tr> 
   <th></th> 
   <th>Name</th> 
   <th>Occupation</th> 
   <th>Born</th> 
   <th>Died</th> 
   <th>age</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <th>0</th> 
   <td>Rosaline Franklin</td> 
   <td>Chemist</td> 
   <td>1920-07-25</td> 
   <td>1958-04-16</td> 
   <td>37</td> 
  </tr> 
  <tr> 
   <th>1</th> 
   <td>William Gosset</td> 
   <td>Statistician</td> 
   <td>1876-06-13</td> 
   <td>1937-10-16</td> 
   <td>61</td> 
  </tr> 
 </tbody> 
</table>

persons = pd.DataFrame({ 
        'Name':['Rosaline Franklin','William Gosset'],
        'Occupation':['Chemist','Statistician'],
        'Born':['1920-07-25','1876-06-13'],
        'Died':['1958-04-16','1937-10-16'],
        'Age':[37,61]},columns=['Occupation','Born','Died','Age'],index=['Rosaline Franklin','William Gosset'])
    print(persons)

Occupation        Born        Died  Age
    Rosaline Franklin       Chemist  1920-07-25  1958-04-16   37
    William Gosset     Statistician  1876-06-13  1937-10-16   61

### 使用有顺序的字典 ###

from collections import OrderedDict
    
    persons = pd.DataFrame(OrderedDict([
        ('Name',['Rosaline Franklin','William Gosset']),
        ('Occupation',['Chemist','Statistician']),
        ('Born',['1920-07-25','1876-06-13']),
        ('Died',['1958-04-16','1937-10-16']),
        ('Age',[37,61])
        ]))

print(persons)

Name    Occupation        Born        Died  Age
    0  Rosaline Franklin       Chemist  1920-07-25  1958-04-16   37
    1     William Gosset  Statistician  1876-06-13  1937-10-16   61