如何展平熊猫的多指标?

原文:https://www . geeksforgeeks . org/如何展平熊猫中的多索引/

在本文中,我们将讨论如何在熊猫中展平多索引。

展平所有级别的多指标:

在这种方法中,我们将通过使用 reset_index() 函数来平整数据帧的所有级别。

语法:

dataframe.reset_index(inplace=True)

注意: Dataframe 是输入数据帧,我们必须创建 dataframe MultiIndex。

语法:

MultiIndex.from_tuples([(tuple1),.......,(tuple n),names=[column_names])

论据:

  • 元组是值
  • 列名是每个元组值中的列名

:

在这个例子中,我们将创建一个带有 multiIndex 的数据框架,并用 python 编程语言显示它。

Python 3

import pandas as pd

# create DataFrame muktiindexex
data = pd.MultiIndex.from_tuples([('Web Programming', 'php', 'sub1'),
                                  ('Scripting', 'python', 'sub2'),
                                  ('networks', 'computer network', 'sub3'),
                                  ('architecture', 'computer organization', 'sub4'),
                                  ('coding', 'java', 'sub5')],
                                 names=['Course', 'Subject name', 'subject id'])

# create dataframe with student marks
data = pd.DataFrame({'ravi': [98, 89, 90, 88, 93],
                     'reshma': [78, 89, 80, 98, 63], 
                     'sahithi': [78, 89, 80, 98, 63]},  
                    index=data)

# display
data

输出:

现在,我们将所有级别的指数拉平:

Python 3

import pandas as pd

# create DataFrame muktiindexex
data = pd.MultiIndex.from_tuples([('Web Programming', 'php', 'sub1'),
                                  ('Scripting', 'python', 'sub2'),
                                  ('networks', 'computer network', 'sub3'),
                                  ('architecture', 'computer organization', 'sub4'),
                                  ('coding', 'java', 'sub5')],
                                 names=['Course', 'Subject name', 'subject id'])

# create dataframe with student marks

data = pd.DataFrame({'ravi': [98, 89, 90, 88, 93], 
                     'reshma': [78, 89, 80, 98, 63],
                     'sahithi': [78, 89, 80, 98, 63]},
                    index=data)

# flatten the index of all levels
data.reset_index(inplace=True)

# display
data

输出:

展平特定级别的多指标

通过使用特定的级别,我们可以使用以下语法:

dataframe.reset_index(inplace=True,level=['level_name'])

在哪里

  • 数据帧是输入数据帧
  • level_name 是多索引级别的名称

示例:

在这个例子中,我们将创建一个数据框架,展平 multiIndex 的特定级别,并以 python 编程语言显示它。

Python 3

import pandas as pd

# create DataFrame muktiindexex
data = pd.MultiIndex.from_tuples([('Web Programming', 'php', 'sub1'),
                                  ('Scripting', 'python', 'sub2'),
                                  ('networks', 'computer network', 'sub3'),
                                  ('architecture', 'computer organization', 'sub4'),
                                  ('coding', 'java', 'sub5')],
                                 names=['Course', 'Subject name', 'subject id'])

# create dataframe with student marks

data = pd.DataFrame({'ravi': [98, 89, 90, 88, 93], 
                     'reshma': [78, 89, 80, 98, 63],
                     'sahithi': [78, 89, 80, 98, 63]},
                    index=data)

# flatten the index of level with course column
data.reset_index(inplace=True, level=['Course'])

# display
data

输出:

我们也可以指定多个级别;

Python 3

import pandas as pd

# create DataFrame muktiindexex
data = pd.MultiIndex.from_tuples([('Web Programming', 'php', 'sub1'),
                                  ('Scripting', 'python', 'sub2'),
                                  ('networks', 'computer network', 'sub3'),
                                  ('architecture', 'computer organization', 'sub4'),
                                  ('coding', 'java', 'sub5')],
                                 names=['Course', 'Subject name', 'subject id'])

# create dataframe with student marks

data = pd.DataFrame({'ravi': [98, 89, 90, 88, 93],
                     'reshma': [78, 89, 80, 98, 63], 
                     'sahithi': [78, 89, 80, 98, 63]}, 
                    index=data)

# flatten the index of level with course 
# and subject id columns
data.reset_index(inplace=True, level=['Course', 'subject id'])

# display
data

输出:

使用 to_records()方法

这是一个 pandas 模块方法,用于将多索引数据帧转换成每个记录并显示。

语法:

dataframe.to_records()

示例:

Python 3

import pandas as pd

# create DataFrame muktiindexex
data = pd.MultiIndex.from_tuples([('Web Programming', 'php', 'sub1'),
                                  ('Scripting', 'python', 'sub2'),
                                  ('networks', 'computer network', 'sub3'),
                                  ('architecture', 'computer organization', 'sub4'),
                                  ('coding', 'java', 'sub5')],
                                 names=['Course', 'Subject name', 'subject id'])

# create dataframe with student marks

data = pd.DataFrame({'ravi': [98, 89, 90, 88, 93],
                     'reshma': [78, 89, 80, 98, 63],
                     'sahithi': [78, 89, 80, 98, 63]}, 
                    index=data)

pd.DataFrame(data.to_records())

输出: