示例代码 2: 使用 apply 返回多列 importpandasaspd# 创建一个 DataFramedf=pd.DataFrame({'A':range(1,6),'B':['pandasdataframe.com'for_inrange(5)]})# 定义一个函数,返回多个新的列值defmultiple_columns(row):returnpd.Series([row['A']*2,row['A']*3],index=['double','triple'])# 应用...
In Pandas, the apply() function can indeed be used to return multiple columns by returning a pandas Series or DataFrame from the applied function. In this article, I will explain how to return multiple columns from the pandas apply() function....
To apply a function that returns multiple values to rows in pandas DataFrame, we will define a function for performing some operations on the values, and then finally we will return all the values in the form of a series. Note To work with pandas, we need to importpandaspackage fi...
20,30],'C':['pandasdataframe.com','modify','columns']})# 定义一个函数,如果数值大于10,加10defadd_ten(x):returnx+10ifx>10elsex# 对'A'和'B'列应用条件函数df[['A','B']]=df[['A','B']].applymap(add_ten)print(df)
hexdigest(), 16) h = k % 2147483648 return h 1. Pandas测试 读取数据集,记录该操作耗时: import pandas as pd df_data = pd.read_csv(data_file, names=col_list) 显示原始数据,df_data.head() 运行apply函数,并记录该操作耗时: for col in df_data.columns: df_data[col] = df_data.apply(...
(self, key, value) 1284 ) 1285 1286 check_dict_or_set_indexers(key) 1287 key = com.apply_if_callable(key, self) -> 1288 cacher_needs_updating = self._check_is_chained_assignment_possible() 1289 1290 if key is Ellipsis: 1291 key = slice(None) ~/work/pandas/pandas/pandas/core/...
Yields below output. When you apply count on the entire DataFrame, pretty much all columns will have the same values. So when you want togroup by countjustselect a column, you can even select from your group columns. # Group by multiple columns and get ...
sql中的case when的功能是实现单列或者多列的条件统计，其实Pandas也可以实现的，比如万能的apply方法，...
3 Applying different functions to DataFrame columns By passing a dict toaggregateyou can apply a different aggregation to the columns of a DataFrame: In [94]: grouped.agg({"C": np.sum,"D":lambdax: np.std(x, ddof=1)}) Out[94]: ...
df.columns() # 查看字段()名称 df.describe() # 查看汇总统计 s.value_counts() # 统计某个值出现次数 df.apply(pd.Series.value_counts) # 查看DataFrame对象中每列的唯值和计数 df.isnull().any() # 查看是否有缺失值 df[df[column_name].duplicated()] # 查看column_name字段数据重复的数据信息 ...