python-3.5

来源： https://stackoverflow.com/questions/39458193/using-list-tuple-etc-from-typing-vs-directly-referring-type-as-list-tuple-etc

问题 Could I specify exclusive type? Something like this: def foo(bar: Not[str]) -> None: assert not isinstance(bar, str) print(type(bar)) 回答1: PEP 484 does not include a built-in way of specifying a "blacklisted" type. Doing that kind of thing typically doesn't really make sense -- the only reason I can think of why you might want to do something like this is if you wanted to distinguish between str and Iterable[str] or Sequence[str] in some fashion. If that's the case, PEP 484 unfortunately

问题 Could I specify exclusive type? Something like this: def foo(bar: Not[str]) -> None: assert not isinstance(bar, str) print(type(bar)) 回答1: PEP 484 does not include a built-in way of specifying a "blacklisted" type. Doing that kind of thing typically doesn't really make sense -- the only reason I can think of why you might want to do something like this is if you wanted to distinguish between str and Iterable[str] or Sequence[str] in some fashion. If that's the case, PEP 484 unfortunately

问题 I have to process a huge pandas.DataFrame (several tens of GB) on a row by row bases, where each row operation is quite lengthy (a couple of tens of milliseconds). So I had the idea to split up the frame into chunks and process each chunk in parallel using multiprocessing . This does speed-up the task, but the memory consumption is a nightmare. Although each child process should in principle only consume a tiny chunk of the data, it needs (almost) as much memory as the original parent process

问题 I have to process a huge pandas.DataFrame (several tens of GB) on a row by row bases, where each row operation is quite lengthy (a couple of tens of milliseconds). So I had the idea to split up the frame into chunks and process each chunk in parallel using multiprocessing . This does speed-up the task, but the memory consumption is a nightmare. Although each child process should in principle only consume a tiny chunk of the data, it needs (almost) as much memory as the original parent process

问题 I am debugging a Python ( 3.5 ) program with PyCharm ( PyCharm Community Edition 2016.2.2 ; Build #PC-162.1812.1, built on August 16, 2016 ; JRE: 1.8.0_76-release-b216 x86 ; JVM: OpenJDK Server VM by JetBrains s.r.o ) on Windows 10. The problem: when stopped at some breakpoints, the Debugger window is stuck at "Collecting data", which eventually timeout. (with Unable to display frame variables ) The data to be displayed is neither special, nor particularly large. It is somehow available to

问题 How can I fill bar graph's bars with image like the pattern does? The following are my discoveries or related questions: So far I have find this useful post. It helps me to output a graph like this. This is already very near to what I want. However, I would like to have this effect like this post. Unfortunately, this is a JS post. I just want to fill the bar with images once it reaches 1, fill twice when it reaches 2 accordingly. And for decimal, it crops the image or just resize it to fit

问题 Im getting the error as shown in title with this environment setup. Apache2 with mod_wsgi ,Python 3.5, Django 2.0.2 . I'm using virtualevn. my virtual env is in : /home/santosh/Documents/project/project/ and django app is in /home/santosh/Documents/project/Reports Below is the content of wsgi.py file import os, sys sys.path.append('/home/santosh/Documents/project/Reports/Reports') sys.path.append('/home/santosh/Documents/project/Reports') sys.path.append('/home/santosh/Documents/project

问题 Im getting the error as shown in title with this environment setup. Apache2 with mod_wsgi ,Python 3.5, Django 2.0.2 . I'm using virtualevn. my virtual env is in : /home/santosh/Documents/project/project/ and django app is in /home/santosh/Documents/project/Reports Below is the content of wsgi.py file import os, sys sys.path.append('/home/santosh/Documents/project/Reports/Reports') sys.path.append('/home/santosh/Documents/project/Reports') sys.path.append('/home/santosh/Documents/project

问题 Couldn't able to import psycopg2 Output in python console: import psycopg2 Traceback (most recent call last): File "", line 1, in File "/home/user/.py_virtualenvs/verb_py3/lib/python3.5/site-packages/psycopg2/ init .py", line 50, in from psycopg2._psycopg import ( # noqa ImportError: /home/user/.py_virtualenvs/verb_py3/lib/python3.5/site-packages/psycopg2/_psycopg.cpython-35m-x86_64-linux-gnu.so: undefined symbol: PQconninfo 回答1: Installed the psycopg2-binary package solved my issue. pip