小编cit*_*man的帖子

在django应用程序中,我正在运行异步任务,并希望向用户显示进度,错误等.如果存在错误,则应将用户重定向到需要其他输入或某些操作来解决问题的页面.从芹菜工作到前端沟通的最佳方式是什么？

这是伪代码的基本结构:

# views.py
from tasks import run_task

def view_task():
    run_task.delay()
    return render(request, 'template.html')

# tasks.py
from compute_module import compute_fct

@shared_task
def run_task():
    result = compute_fct()

    # how to catch status update messages from compute_module while compute_fct is running??

    if result == 'error':
        handle_error()
    else:
        handle_succes()     

# compute_module
import pandas as pd

def compute_fct():
    # send message: status = loading file
    df = pd.read_csv('test.csv')
    # send message: status = computing
    val = df['col'].mean()

    if val is None:
        return {'status':'error'}
    else: …

Pyspark n00b ...如何用自身的子串替换列？我正在尝试从字符串的开头和结尾删除选定数量的字符.

from pyspark.sql.functions import substring
import pandas as pd
pdf = pd.DataFrame({'COLUMN_NAME':['_string_','_another string_']})
# this is what i'm looking for...
pdf['COLUMN_NAME_fix']=pdf['COLUMN_NAME'].str[1:-1] 

df = sqlContext.createDataFrame(pdf)
# following not working... COLUMN_NAME_fix is blank
df.withColumn('COLUMN_NAME_fix', substring('COLUMN_NAME', 1, -1)).show() 

这是非常接近但与其他列的最后一个字符略有不同的Spark Dataframe列.然后在PySpark SQL中有这个 LEFT和RIGHT函数