# encoding=utf-8
import pandas as pd
# 定義一個(gè)列表
a = [1, 2, 3, 4]
s1 = pd.Series(a)
print(s1)

`s1 = pd.Series(a, index=["a", "b", "c", "d"])`

# encoding=utf-8
import pandas as pd
import numpy as np
# 定義數(shù)組
arr = np.arange(1, 5)
s2 = pd.Series(arr)
print(s2)

# encoding=utf-8
import pandas as pd
# 創(chuàng)建一個(gè)字典
dic = {"name": "丁少俠", "age": 20, "grade": [100, 99, 88]}
s3 = pd.Series(dic)
print(s3)

s3 = pd.Series(dic, index=["grade", "name", "age"])

s3 = pd.Series(dic, index=["grade", "name", "age", "sex"])

s3["sex"]="男"

s3["hobby"] = ["code,basketball,sleep"]

pip install pandas

Series(data=None, index=None, dtype=None, name=None, copy=False, fastpath=False)

#Series實(shí)例
import pandas as pd
from pandas import Series
seri=pd.Series([3,5,-2,9],index=['a','b','c','d'])
print(seri)
print(type(seri))
#輸出
a    3
b    5
c   -2
d    9
dtype: int64
<class 'pandas.core.series.Series'>

import pandas as pd
from pandas import Series
seri=pd.Series([3,5,-2,9],index=['a','b','c','d'])
print(seri.values)
print(type(seri.values))
#輸出
[ 3 ?5 -2 ?9]
<class 'numpy.ndarray'> #生成series時(shí)傳入的值是list結(jié)構(gòu)，輸出的仍是 ndarray結(jié)構(gòu)

series.index,：以pandas index 結(jié)構(gòu)輸出
import pandas as pd
from pandas import Series
seri=pd.Series([3,5,-2,9],index=['a','b','c','d'])
print(seri.index)
print(type(seri.index))
#輸出：
Index(['a', 'b', 'c', 'd'], dtype='object')
<class 'pandas.core.indexes.base.Index'>

import pandas as pd
from pandas import Series
seri=pd.Series([3,5,-2,9])
seri.index=["a","b","c","d"]
print(seri["a"]) #通過索引名稱查找，類似字典
print(seri[0:3])#通過位置切片查找，類似列表/數(shù)組
#輸出
3
a ? ?3
b ? ?5
c ? -2

import pandas as pd
from pandas import Series
dic={"a":"5","n":"6","k":"0"}
seri=pd.Series(dic)
print(seri)
#輸出
a ? ?5
n ? ?6
k ? ?0

import pandas as pd
from pandas import Series
dic={"a":'',"n":"","k":"0"}
seri=pd.Series(dic)
print(seri.isnull)
#輸出：
<bound method Series.isnull of a ? ? n ? ??
k ? ?0

import numpy as np
import pandas as pd
from pandas import Series
dic={"a":np.nan,"n":np.nan,"k":"f"}
seri=pd.Series(dic)
print(seri.isnull().all())
#輸出：
False
#ps: 判斷series中是否都為缺失數(shù)據(jù)：series.isnull().any()，輸出布爾值

import pandas as pd
from pandas import DataFrame
from pandas import Series
data=["a","k","m","a","w","m","9"]
obj=Series(data)
uniques=obj.unique()
print(uniques)
#輸出：
['a' 'k' 'm' 'w' '9']
#注：也可以用python 的set函數(shù)，
print(set(data))
#輸出
{'m', 'w', '9', 'a', 'k'}
#區(qū)別：
set去重后會(huì)改變?cè)瓉?lái)的順序，而unique不會(huì)
set生成的事set對(duì)象 <class 'set'>，而unique生成的事ndarray對(duì)象 <class 'numpy.ndarray'>