📜  如何在 Pandas DataFrame 中设置单元格值?

📅  最后修改于: 2022-05-13 01:55:39.453000             🧑  作者: Mango

如何在 Pandas DataFrame 中设置单元格值?

在本文中,我们将讨论如何在Python中设置 Pandas DataFrame 中的单元格值。

方法一:使用 pandas.dataframe.at 方法

此方法用于为现有值设置值或设置新记录。

语法

dataframe.at[index, 'column_name'] = value

在哪里,

  • 数据框是输入数据框
  • index 是要插入的位置
  • column_name 是插入值的列
  • value 是要插入的值

示例

Python3
# import pandas module
import pandas as pd
  
# create a dataframe
# with 3 rows amd 3  columns
data = pd.DataFrame({
    'name': ['sireesha', 'ravi', 'rohith', 'pinkey', 'gnanesh'],
    'subjects': ['java', 'php', 'html/css', 'python', 'R'],
    'marks': [98, 90, 78, 91, 87]
})
  
# set value at 6 th location for name column
data.at[5, 'name'] = 'sri devi'
  
# set value at 6 th location for subjects column
data.at[5, 'subjects'] = 'jsp'
  
  
# set value at 6 th location for marks column
data.at[5, 'marks'] = 100
  
# set value at 4 th location for name column
data.at[4, 'name'] = 'siva nagulu'
  
# set value at 4 th location for subjects column
data.at[4, 'subjects'] = 'react-js'
  
  
# set value at 4 th location for marks column
data.at[4, 'marks'] = 80
  
# display
data


Python3
# import pandas module
import pandas as pd
  
# create a dataframe
# with 3 rows amd 3  columns
data = pd.DataFrame({
    'name': ['sireesha', 'ravi', 'rohith', 'pinkey', 'gnanesh'],
    'subjects': ['java', 'php', 'html/css', 'python', 'R'],
    'marks': [98, 90, 78, 91, 87]
})
  
# set value at 6 th location for name column
data.loc[5, 'name'] = 'sri devi'
  
# set value at 6 th location for subjects column
data.loc[5, 'subjects'] = 'jsp'
  
  
# set value at 6 th location for marks column
data.loc[5, 'marks'] = 100
  
# set value at 4 th location for name column
data.loc[4, 'name'] = 'siva nagulu'
  
# set value at 4 th location for subjects column
data.loc[4, 'subjects'] = 'react-js'
  
  
# set value at 4 th location for marks column
data.loc[4, 'marks'] = 80
  
# display
data


输出

方法二:使用 loc() 方法

这里我们使用 loc() 方法根据行索引和列名设置列值

语法

dataframe.loc[index, 'column_name'] = value

在哪里,

  • 数据框是输入数据框
  • index 是要插入的位置
  • column_name 是插入值的列
  • value 是要插入的值

示例

Python3

# import pandas module
import pandas as pd
  
# create a dataframe
# with 3 rows amd 3  columns
data = pd.DataFrame({
    'name': ['sireesha', 'ravi', 'rohith', 'pinkey', 'gnanesh'],
    'subjects': ['java', 'php', 'html/css', 'python', 'R'],
    'marks': [98, 90, 78, 91, 87]
})
  
# set value at 6 th location for name column
data.loc[5, 'name'] = 'sri devi'
  
# set value at 6 th location for subjects column
data.loc[5, 'subjects'] = 'jsp'
  
  
# set value at 6 th location for marks column
data.loc[5, 'marks'] = 100
  
# set value at 4 th location for name column
data.loc[4, 'name'] = 'siva nagulu'
  
# set value at 4 th location for subjects column
data.loc[4, 'subjects'] = 'react-js'
  
  
# set value at 4 th location for marks column
data.loc[4, 'marks'] = 80
  
# display
data

输出