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

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

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]})

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()

	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 = 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