我第一次在 Python 中尝试多线程。我看到 documentation here .以下是我的示例代码
from multiprocessing.dummy import Pool as ThreadPool
pool = ThreadPool(4)
mylist = [3,4,5,6,7,8, ..., 5]
results = pool.map(my_method, my_list) # from docs it is clear that pool.map takes method and argument as a list
def my_method(mylist):
data = []
for i in range (len(mylist)):
# do something using mylist = subdata
data.append(subdata)
return data
它返回以下错误
Traceback (most recent call last):
File "C:/Users/algorithm.py", line 30, in my_method
for i in range (len(mylist)):
TypeError: object of type 'float' has no len()
从文档中可以清楚地看出 pool.map 采用函数和列表 ( see this tutorial too ) 但为什么它假设 my_list 为 float 给出这个错误。有什么建议 ？谢谢
请您参考如下方法:
这段代码有什么作用？
results = pool.map(my_method, my_list)
它多次调用 my_method，每次从您的列表 my_list 中传入一个元素，请参阅:https://docs.python.org/2/library/multiprocessing.html#multiprocessing.pool.multiprocessing.Pool.map
map(func, iterable[, chunksize]) A parallel equivalent of the map() built-in function (it supports only one iterable argument though). It blocks until the result is ready.
This method chops the iterable into a number of chunks which it submits to the process pool as separate tasks. The (approximate) size of these chunks can be specified by setting chunksize to a positive integer.
所以
for i in range (len(mylist)):
实际上是在 int 或 float 上调用 len 是不是你的意思
for i in range (mylist):
