python-3.5

问题 I was trying to override the functionality of isspace() for my personal experiments, so I tried to navigate to the origin source of it. I landed up at builtins.py at the following implementation: def isspace(self): # real signature unknown; restored from __doc__ """ S.isspace() -> bool Return True if all characters in S are whitespace and there is at least one character in S, False otherwise. """ return False This made me curious as to where is this builtin implemented but couldn't figure

问题 I am trying to write a dynamic program(to parse json files based on their tags) in python and i am using Python exec function to do that. But the program is failing when exec statement is in a function. RUN 1: Exec in a function: import json from pandas.io.json import json_normalize import sys def param(dfile): aString = "['widget']['image']~['widget']['window']~['widget']['text']" for nd_part in aString.split('~'): exec("temp = %s%s"%(dfile,nd_part)) print(temp) if __name__ == "__main__":

问题 I tried to install some libraries with pip install , however I can't because everytime I get: PermissionError: [WinError 5] Permission denied: 'c:\\program files <x86>\\python35-32\\Lib\\site-packages\\PIL Wanted to install PIL, ImageTK, Pillow etc. I get this error everytime, how can I fix this? I tried easy_install too, didn't work. I checked some questions about this but none of them worked either, there are no answer. 回答1: Windows blocks access to this folder for normal users. You have to

问题 I tried to install some libraries with pip install , however I can't because everytime I get: PermissionError: [WinError 5] Permission denied: 'c:\\program files <x86>\\python35-32\\Lib\\site-packages\\PIL Wanted to install PIL, ImageTK, Pillow etc. I get this error everytime, how can I fix this? I tried easy_install too, didn't work. I checked some questions about this but none of them worked either, there are no answer. 回答1: Windows blocks access to this folder for normal users. You have to

问题 Given these strings: "1 + 2" "apple,pear" How can I use Python 3(.5) to determine that the first string contains a math problem and nothing else and that the second string does not? 回答1: Here is a way to do it: import ast UNARY_OPS = (ast.UAdd, ast.USub) BINARY_OPS = (ast.Add, ast.Sub, ast.Mult, ast.Div, ast.Mod) def is_arithmetic(s): def _is_arithmetic(node): if isinstance(node, ast.Num): return True elif isinstance(node, ast.Expression): return _is_arithmetic(node.body) elif isinstance(node

问题 Given these strings: "1 + 2" "apple,pear" How can I use Python 3(.5) to determine that the first string contains a math problem and nothing else and that the second string does not? 回答1: Here is a way to do it: import ast UNARY_OPS = (ast.UAdd, ast.USub) BINARY_OPS = (ast.Add, ast.Sub, ast.Mult, ast.Div, ast.Mod) def is_arithmetic(s): def _is_arithmetic(node): if isinstance(node, ast.Num): return True elif isinstance(node, ast.Expression): return _is_arithmetic(node.body) elif isinstance(node

问题 Let's say I have two bytearray, b = bytearray(b'aaaaaa') b1 = bytearray(b'bbbbbb') file_out = open('bytes.bin', 'ab') file_out.write(b) file_out.write(b1) this code will create a .bin file which contains two bytearrays how to read this file and store those two variables also decode them back to string? my goal is to transfer these bytes for other programs to read by making a file. I'm not sure if this bytearray + appending is a good idea. Thanks 回答1: Pythons pickle is meant for storing and

问题 In python 3.5.1 one can make use of await/async, however, to use it (as I undestand), you need to have awaitable object . An awaitable object is an object that defines __await__() method returning an iterator. More info here. But I can not google out any example of having this, since most examples have some sort of asyncio.sleep(x) to mimic awaitable object. My ultimate goal is to make simple websocket serial server, however, I can't pass this first step. This is my (non working code). import

问题 I have a multiprocessing script with pool.map that works. The problem is that not all processes take as long to finish, so some processes fall asleep because they wait until all processes are finished (same problem as in this question). Some files are finished in less than a second, others take minutes (or hours). If I understand the manual (and this post) correctly, pool.imap is not waiting for all the processes to finish, if one is done, it is providing a new file to process. When I try

问题 I have a package for python 3.5 and 3.6 that has optional dependencies for which I want tests (pytest) that run on either version. I made a reduced example below consisting of two files, a simple __init__.py where the optional package "requests" (just an example) is imported and a flag is set to indicate the availability of requests. mypackage/ ├── mypackage │ └── __init__.py └── test_init.py The __init__.py file content: #!/usr/bin/env python # -*- coding: utf-8 -*- requests_available = True