import os,time from multiprocessing import Pool def work(n): print('%s run' %os.getpid()) time.sleep(3) return n**2 if __name__ == '__main__': p=Pool(3) #进程池中从无到有创建三个进程,以后一直是这三个进程在执行任务 res_l=[] for i in
问如何在python中对dataframe列内容使用应用函数/for循环EN作为背景，我正在查看数据科学家职位和职位描述的...
dataframe循环修改内存比如series *= -1会非常慢,用pd.concat来减少内存复制,或如下办法 # # 方法2越拼越慢 # X_ret = pd.DataFrame([]) # for corr reduction # y_ = y_.astype(np.float16) # for i in X_df: # X_ret = pd.concat([X_ret, X_df[i] * y_.values], axis=1) # prin...
Dask DataFrame was originally designed to scale Pandas, orchestrating many Pandas DataFrames spread across many CPUs into a cohesive parallel DataFrame. Because cuDF currently implements only a subset of the Pandas API, not all Dask DataFrame operations work with cuDF. 3. 最装逼的办法就是只用pandas...
#将DataFrame注册为table. schemaPeople = sqlContext.createDataFrame(people) schemaPeople.registerTempTable("people") # 执行sql查询,查下条件年龄在13岁到19岁之间 teenagers = sqlContext.sql("SELECT name,age FROM people WHERE age >= 13 AND age <= 19") ...
("default payment next month") # convert the dataframe values to array X_test = test_df.values print(f"Training with data of shape {X_train.shape}") clf = GradientBoostingClassifier( n_estimators=args.n_estimators, learning_rate=args.learning_rate ) clf.fit(X_train, y_train) y_pred ...
("default payment next month") # convert the dataframe values to array X_test = test_df.values print(f"Training with data of shape {X_train.shape}") clf = GradientBoostingClassifier( n_estimators=args.n_estimators, learning_rate=args.learning_rate ) clf.fit(X_train, y_train) y_pred ...
【例17】对于DataFrame格式的某公司销售数据workdata.csv,存储在本地的数据的形式如下,请利用Python的数据透视表分析计算每个地区的销售总额和利润总额。 关键技术:在pandas中透视表操作由pivot_table()函数实现,其中在所有参数中,values、index、 columns最为关键,它们分别对应Excel透视表中的值、行、列。程序代码如下...
首先准备三组DataFrame数据: import pandas as pddf1 = pd.DataFrame({'id': ['001', '002', '003'], 'num1': [120, 114, 123], 'num2': [110, 102, 121], 'num3': [113, 124, 128]})df2 = pd.DataFrame({'id': ['004', '005'], 'num1': [120, 101], 'num2': [113, 12...
Fix from_dataframe (#60) Feb 19, 2025 pyproject.toml add tests for py3.13 (#59) Feb 18, 2025 Repository files navigation README Code of conduct MIT license PyFlwDir: Fast methods to work with hydro- and topography data in pure Python ...