izip不使用Python 3.x。

I am trying to import the izip module like so:

我正在尝试导入izip模块:

from itertools import izip

However after recently changing over from Python 2.7 to 3 - it doesn't seem to work.

然而，在最近从Python 2.7转换到3之后，它似乎并不起作用。

I am trying to write to a csv file:

我试着写一个csv文件:

writer.writerows(izip(variable1,2))

But I have no luck. Still encounter an error.

但是我没有运气。还遇到一个错误。

2 个解决方案

#1

In Python 3 the built-in zip does the same job as itertools.izip in 2.x (returns an iterator instead of a list). The zip implementation is almost completely copy-pasted from the old izip, just with a few names changed and pickle support added.

在Python 3中，内置的zip与itertools做同样的工作。izip在2。返回一个迭代器而不是列表。zip实现几乎完全复制了旧的izip，只是添加了一些名称和pickle支持。

Here is a benchmark between zip in Python 2 and 3 and izip in Python 2:

这里是Python 2和3之间的zip和Python 2中的izip之间的基准:

Python 2.7:

Python 2.7:

from timeit import timeit

print(timeit('list(izip(xrange(100), xrange(100)))',
             'from itertools import izip',
             number=500000))

print(timeit('zip(xrange(100), xrange(100))', number=500000))

Output:

输出:

1.9288790226
1.2828938961

Python 3:

Python 3:

from timeit import timeit

print(timeit('list(zip(range(100), range(100)))', number=500000))

Output:

输出:

1.7653984297066927

In this case since zip's arguments must support iteration you can not use 2 as its argument. So if you want to write 2 variable as a CSV row you can put them in a tuple or list:

在本例中，由于zip的参数必须支持迭代，所以不能使用2作为其参数。如果你想把2个变量写成CSV行你可以把它们放到一个元组或列表中:

writer.writerows((variable1,2))

Also from itertools you can import zip_longest as a more flexible function which you can use it on iterators with different size.

同样，您可以从itertools导入zip_最长作为一个更灵活的函数，您可以在不同大小的迭代器上使用它。

#2

One of the ways which helped me is:

其中一个帮助我的方法是:

try:
    from itertools import izip as zip
except ImportError: # will be 3.x series
    pass