importpandasaspd# 创建一个DataFramedf=pd.DataFrame({'A':[10,20,30],'B':[20,30,40],'C':['pandasdataframe.com','example','test']})# 使用lambda函数将两列数值相加df['A+B']=df.apply(lambdarow:row['A']+row['B'],axis=1)print(df) Python Copy Output: 示例3:条件修改多个列 import...
'pandasdataframe.com','pandasdataframe.com']})# 使用 apply 和 lambda 来创建一个新列,根据条件修改值df['New Column']=df.apply(lambdarow:row['A']+row['B']ifrow['A']>150elserow['B'],axis=1)print(df)
# 复杂操作(Apply) start = time.time() pdf['price_category'] = pdf['price'].apply(lambda x: 1 if x > 50 else 0) pandas_apply_time = time.time() - start start = time.time() gdf['price_category'] = gdf['price'].apply(lambda x: 1 if x > 50 else 0) cudf_apply_time = ...
pandas.DataFrame.apply() can be used along with the Python lambda function to apply a custom operation to all columns in a DataFrame. A lambda function is a small anonymous function that can take any number of arguments and execute an expression....
方法append_to_multiple和select_as_multiple可以同时从多个表中执行追加/选择操作。其思想是有一个表(称之为选择器表),你在这个表中索引大部分/全部列,并执行你的查询。其他表是数据表,其索引与选择器表的索引匹配。然后你可以在选择器表上执行非常快速的查询,同时获取大量数据。这种方法类似于拥有一个非常宽的...
We are supposed to find the unique values from multiple groupby.Getting unique values from multiple columns in a pandas groupbyFor this purpose, we can use the combination of dataframe.groupby() and apply() method with the specified lambda expression. The groupby() method is a simple but ...
df.apply(lambda row: '|'.join(filter(pd.notna, [row['source_1'], row['source_2']])), axis=1)sort_values(by=multiple columns) sort_values可以不止一个column,可以多个。 df.sort_values(by=['name', 'number']) 还可以指定ascending=[False, True]比较两个dataframe是否相等 ...
s2.map_index(lambda v: "color:pink;" if v>4 else "color:darkblue;", axis=0) s2.apply_index(lambda s: np.where(s.isin(["A", "B"]), "color:pink;", "color:darkblue;"), axis=1) 代码语言:javascript 代码运行次数:0 运行 复制 [29]: A B C D 0 1.764052 0.400157 0.978738...
Applying Lambda Function on Multiple Columns UsingDataFrame.assign()Method We can also apply the Lambda function on multiple columns using thedataframe.assign()method in PandasDataFrame. For example, we have four columnsStudent Names,Computer,Math, andPhysics. We applied a Lambda function on multiple...
Apply Function on DataFrame Index How to strip the whitespace from Pandas DataFrame headers? DataFrame object has no attribute sort How to replace negative numbers in Pandas Data Frame by zero? Lambda including if, elif and else Pandas: Find percentile stats of a given column ...