DataFrame.apply('function','condition') Note To work with pandas, we need to importpandaspackage first, below is the syntax: import pandas as pd Let us understand with the help of an example: Python program to apply a function to a single column in pandas DataFrame ...
importpandasaspd# 创建 DataFramedf=pd.DataFrame({'A':range(1,6),'B':[10*xforxinrange(1,6)],'C':['pandasdataframe.com'for_inrange(5)]})# 定义一个函数,操作多列defmodify_columns(row):row['A']=row['A']*100row['B']=row['B']+5returnrow# 应用函数到 DataFramedf=df.apply(mod...
How to Apply a Function to Multiple Columns of DataFrame?To apply a function to multiple columns of a Pandas DataFrame, you can simply use the DataFrame.apply() method by specifying the column names. The method itself takes a function as a parameter that has to be applied on the columns....
0 or ‘index’:函数按列处理(apply function to each column) 1 or ‘columns’:函数按行处理( apply function to each row) # 只处理指定行、列,可以用行或者列的 name 属性进行限定df5=df.apply(lambdad:np.square(d)ifd.name=="a"elsed,axis=1)print("-"*30,"\n",df5)# 仅对行"a"进行操作...
This page is based on a Jupyter/IPython Notebook: download the original .ipynbimport pandas as pd Use .apply to send a column of every row to a function You can use .apply to send a single column to a function. This is useful when cleaning up data - converting forma...
Apply a function along an axis of the DataFrame. Objects passed to the function are Series objects whose index is either the DataFrame's index (``axis=0``) or the DataFrame's columns (``axis=1``). By default (``result_type=None``), the final return type ...
function df['new_col'] = df.apply(lambda row : row[0]+row[1]+row[2], axis=1) # Example 3: Add 3 to each column of a row df2 = df.apply(lambda row : pd.Series([row[0]+3,row[1]+3,row[2]+3]), axis=1) # Example 4: Apply function NumPy.sum() to each row df['...
import pandas as pd # 定义一个函数,该函数将在每一行中应用 def my_function(row): return pd.Series([row['column1'] * 2, row['column2'] * 3]) # 创建一个DataFrame data = {'column1': [1, 2, 3], 'column2': [4, 5, 6]} df = pd.DataFrame(data) # 使用apply函数将my_fu...
DataFrame(data) print('Before applying function: ') print(df) # applying function to each row in # dataframe and storing result in a new column df = df.apply(lambda row : replace(row)) print('After Applying Function: ') # printing the new dataframe print(df) if __name__ == '__...
apply()堪称pandas中最好用的方法,其使用方式跟map()很像,主要传入的主要参数都是接受输入返回输出。 但相较于map()针对单列Series进行处理,一条apply()语句可以对单列或多列进行运算,覆盖非常多的使用场景。 下面我们来分别介绍: 单列数据 这里我们参照2.1向apply()中传入lambda函数: ...