pandas資料索引 loc iloc和ix

2021-08-14 10:30:59 字數 2192 閱讀 7276

1、loc

通過行標籤索引行資料

(1)、loc[『d』]:獲取第』d』行資料

import pandas as pd  

data = [[1,2,3],[4,5,6]]

index = [『d』,'e']

columns=['a','b','c']

df = pd.dataframe(data=data, index=index, columns=columns)

print(df.loc['e'])

a    4

b 5

c 6

name: 1, dtype: int64

(2)、loc['d':]

獲取第『d』行及之後的多行資料

import pandas as pd  

data = [[1,2,3],[4,5,6]]

index = ['d','e']

columns=['a','b','c']

df = pd.dataframe(data=data, index=index, columns=columns)

print(df.loc['d':])

a  b  c

d 1 2 3

e 4 5 6

(3)、

loc['d',['b']]索引第『d』行第『b』列

import pandas as pd  

data = [[1,2,3],[4,5,6]]

index = ['d','e']

columns=['a','b','c']

df = pd.dataframe(data=data, index=index, columns=columns)

print(df.loc['d',['b']])

b    2

name: d, dtype: int64

通過df.[列標籤]可直接獲取某列資料,但當標籤未知時可通過這種方式獲取列資料

2、iloc

通過行號獲取行資料

(1)、iloc[1]獲取第1行資料

import pandas as pd  

data = [[1,2,3],[4,5,6]]

index = ['d','e']

columns=['a','b','c']

df = pd.dataframe(data=data, index=index, columns=columns)

print(df.iloc[1])

a    4

b 5

c 6

name: e, dtype: int64

(2)、iloc[0:]

獲取第0行及之後的多行資料

import pandas as pd  

data = [[1,2,3],[4,5,6]]

index = ['d','e']

columns=['a','b','c']

df = pd.dataframe(data=data, index=index, columns=columns)

print(df.iloc[0:])

a  b  c

d 1 2 3

e 4 5 6

(3)、iloc[:,[1]]

獲取第1列資料

import pandas as pd  

data = [[1,2,3],[4,5,6]]

index = ['d','e']

columns=['a','b','c']

df = pd.dataframe(data=data, index=index, columns=columns)

print(df.iloc[:,[1]])

b

d 2

e 5

3、ix

前兩種的混合索引,python3已經不使用這種索引方式。

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