如何将gevent用于任务＆＃34;阅读 - 搜索 - 写＆＃34;？

Question

我正在尝试处理以下任务：

1. 读取本地文件中的一行
2. 将该行发送到Web服务以进行查询
3. 将结果写入本地文件

`

def read(fin):
    for query in fin:
        return query

def search(query):
    # Send the query to something like Google Search
    result = google(query)
    return result

def write(fout, result):
    fout.write(result)

`

我参考Gevent教程，但无法弄清楚如何将这三个函数放入gevent。

Answer 1

我不知道你的例子与gevent有关。无论如何，它仍然可以通过下面的示例代码进行处理。

import gevent

def read(fin):
    for query in fin:
        return query

def search(query):
    # Send the query to something like Google Search
    result = google(query)
    return result

def write(fout, result):
    fout.write(result)

# read from different files
input_files = ["input1.json", "input2.json" ... ] 

# write result into output file
fout = open("output.json", 'wb')

# get queries from input files
queries = []
for input_file in input_files:
    with open(input_file, 'rb') as fin:
        queries.append(gevent.joinall([gevent.spawn(read, fin)]))

# store results of queries
results = []
for item in [query for query in queries]:
    results.append(gevent.joinall([gevent.spawn(search, item[0].value)]))

# save results into output file
for item in [result for result in results]:
    gevent.joinall([gevent.spawn(write, fout, item[0].value)])

事物是读取搜索和搜索到写入都有依赖，它不能使用异步方式来实现这一点。因此，在该示例中，它只是可以处理每个函数并逐个保存返回。