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``). 传递给函数的对象是Series对象,其索引是DataFrame的索引(axis=0)或DataFrame的列(axis=1)。 By default (``result_type=None``), the final ret...
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...
df['column3'] = df.apply(apply_fx, axis=1) 以下我們用一個簡單例子開始解說 pandas apply。 簡單例子:透過 pandas apply 計算 BMI 匯入pandas 並定義 df。 我們用一個簡單的體重/身高 dataframe 示範如何計算 BMI。 import pandas as pd df = pd.DataFrame( ...
is inferred from the return type of the applied function. Otherwise, it depends on the `result_type` argument. """ 通过函数介绍,我们知道了以下信息: apply会将自定义的func函数应用在dataframe的每列或者每行上面。 func接收的是每列或者每行转换成的一个Series对象,此对象的索引是行索引(对df每列操作...
import pandas as pd # 创建一个示例DataFrame df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6], 'C': [7, 8, 9]}) # 定义一个函数,用于返回两个新列 def custom_function(row): new_column1 = row['A'] + row['B'] new_column2 = row['B'] - row['C'] return pd...
Spark获取DataFrame中列的方式--col,$,column,apply 1、官方说明 2、使用时涉及到的的包 3、Demo 1、官方说明 df("columnName") // On a specific DataFrame. col("columnName") // A generic column no yet associated with a DataFrame. col("columnName.field") // Extracting a struct field ...
function myFunction(a, b) { ... 腹肌猿 0 411 Select rows from Dataframe - 从Dataframe中选择行 2019-12-05 15:22 − How to select rows from a DataFrame based on column values ... o select rows whose column value equals a scalar, some_value, use ==: df.loc[... andy_...
Use .apply with axis=1 to send every single row to a function You can also send an entire row at a time instead of just a single column. Use this if you need to use multiple columns to get a result. # Create a dataframe from a list of dictionaries rectangles = [...
DataFrame, apply_func: callable, window: int, return_col_num: int, **kwargs): """ rolling with multiple columns on 2 dim pd.Dataframe * the result can apply the function which can return pd.Series with multiple columns call apply function with numpy ndarray :param return_col_num: 返回...
- string function name. - function. - list of functions. - dict of column names -> functions (or list of functions). transform groupby对象的实例方法 调用函数在每个分组上产生一个与原df相同索引的DataFrame,返回与原来对象拥有相同索引且已填充了转换后的值的DataFrame。f返回的值要么是与输入子DataFrame...