当我尝试使用beam.combiners.ToList 的输出作为beam.pvalue.AsSingleton 或beam.pvalue.AsList 的输入以试验侧输入时出现意外错误。我能够使用单个数字（例如：列表的平均值）作为辅助输入，但是对于列表和字典，我得到了例外。对于beam.pvalue.AsSingleton，我得到：
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
<ipython-input-4-0c1df7400a03> in <module>
15 chain_total = chain_1 | chain_2
16
---> 17 chain_1 | beam.Map(m, beam.pvalue.AsList(chain_2))
18
19 chain_total | beam.Map(print)
~/.cache/pypoetry/virtualenvs/prototyping-with-tensorflow-py3.6/lib/python3.6/site-packages/apache_beam/pvalue.py in __init__(self, pcoll)
297 self.pvalue = pcoll
298 self._window_mapping_fn = sideinputs.default_window_mapping_fn(
--> 299 pcoll.windowing.windowfn)
300
301 def _view_options(self):
AttributeError: '_ChainedPTransform' object has no attribute 'windowing'
对于beam.pvalue.AsList，我得到：
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
<ipython-input-7-0c1df7400a03> in <module>
15 chain_total = chain_1 | chain_2
16
---> 17 chain_1 | …我在Acer笔记本电脑上使用Ubuntu 16.04.2 LTS,我正在尝试更新我的pip安装(当前版本:8.1.1).当我运行命令
pip install --upgrade pip
我得到以下输出:
Exception:
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 209, in main
status = self.run(options, args)
File "/usr/lib/python2.7/dist-packages/pip/commands/install.py", line 328, in run
wb.build(autobuilding=True)
File "/usr/lib/python2.7/dist-packages/pip/wheel.py", line 748, in build
self.requirement_set.prepare_files(self.finder)
File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 360, in prepare_files
ignore_dependencies=self.ignore_dependencies))
File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 512, in _prepare_file
finder, self.upgrade, require_hashes)
File "/usr/lib/python2.7/dist-packages/pip/req/req_install.py", line 273, in populate_link
self.link = finder.find_requirement(self, upgrade)
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 442, in find_requirement
all_candidates = self.find_all_candidates(req.name)
File "/usr/lib/python2.7/dist-packages/pip/index.py", line 400, in find_all_candidates
for …