Installation vs community version, new project appears:
Exception from HRESULT: 0x80041FE2Reasons for the problem:
when installing, the Linux related environment was selected. When creating the project, the visual c + + project was created, because these components were not installed, an error was reported
Creating Linux related projects will not.
When installing. Net framework 4.0, you will encounter the following error page,
Next, I will post solutions for you
1. After inputting CMD in the start menu, the CMD command input window will pop up
2. Enter net stop wuauserv in the above CMD command line
3. Continue to enter echo% windir%
4. Change the name of the software distribution folder in the pop-up folder (usually C: Windows)
5. Continue to enter net start wuauserv
6. Install net4.0 again and it will be successful
//If you think the above command is troublesome, you can paste and copy it to the CMD window with the mouse
How to connect pyspark with PostgreSQL
Method 1: the PostgreSQL jar package placed in the spark2/jars path does not work. (error)
Method 2: setting spark. Conf. set in spark. Conf. set (‘spark. Jars’, ‘/ usr/HDP/3.0.1.0-187/spark2/jars/postgresql-42.2.5. Jar’) does not work. (error)
Solution
When starting pyspark, add parameters after it
pyspark –jars / usr/hdp/3.0.1.0-187/spark2/jars/postgresql-42.2.5.jar
That’s fine
Always report an error saying that failed by: Java. Lang. classnotfoundexception: org. PostgreSQL. Driver
After a series of searching to find out the reasons, such as the quotation in the box is wrong, I can’t quote what I need;
Only the writing method as shown in the figure below can be quoted successfully,
In memory of the time I’ve been tossing about, it’s also a small lesson of using gradlew for the first time
String value encountered a warning message, record it
Sending 'const NSString *__strong' to parameter of type 'NSString *' discards qualifiers
The code is written like this
UIKIT_EXTERN const NSString * kNetworkType;
This warning will be issued when using it, and it will be changed to:
UIKIT_EXTERN NSString * const kNetworkType;
If const is placed after nsstring *, there will be no warning.
Recently, I wrote makefile, Encountered the error nm: test. O: file format not recognized. Let’s see:
test.h:
void output();test.cpp:
#include <stdio.h>#include "test.h"void output(){ printf("c is good\n");}compile:
xxxxxx:~/mkfile> g++ -c test.cpp test.h -o test.oxxxxxx:~/mkfile> nm test.onm: test.o: File format not recognizedxxxxxx:~/mkfile>Strange, isn’t it?The reason is that there are too many test. H files. There is no need at all. The compiler will find them automatically as long as you specify the directory. If you change the order of test. H and test. CPP, you will be prompted:
xxxxxx:~/mkfile> g++ -c test.h test.cpp -o test.og++: cannot specify -o with -c or -S with multiple filesxxxxxx:~/mkfile> We have already said that.
It seems that when there is – O, you can go to – C to specify multiple files, which is a huge pit.
Let’s share my teacher Dashen’s AI course. Zero base! Easy to understand! Funny! And yellow jokes! Hope you can join our AI team! https://blog.csdn.net/jiangjunshow
When compiling a Linux program, if there is an error:
“File format not recognized” In general, XXX. O in makefile If it is wrongly written as XXX. C, it can be corrected.
Python 2 writes binary file randomly:
with open('/python2/random.bin','w') as f:
f.write(os.urandom(10))However, using Python 3 will report an error:
TypeError:must be str, not bytesThe reason is: Python 3 adds a new parameter named encoding to the open function, and the default value of this new parameter is “UTF-8”. In this way, when the read and write operations are carried out on the file handle, the system requires the developer to pass in the instance containing Unicode characters instead of the byte instance containing binary data.
resolvent:
Use binary write mode (“WB”) to open the file to be operated, instead of using character write mode (“W”) as before.
The method of adapting both Python 3 and python 2 is as follows
with open('python3/rndom.bin','wb') as f:
f.write(os.urandom(10))There is a similar problem when the file reads data. The solution to this problem is similar: open the file in ‘RB’ mode (binary mode) instead of ‘R’ mode.
Python 2 writes binary file randomly:
with open('/python2/random.bin','w') as f:
f.write(os.urandom(10))However, using Python 3 will report an error:
TypeError:must be str, not bytesThe reason is: Python 3 adds a new parameter named encoding to the open function, and the default value of this new parameter is “UTF-8”. In this way, when the read and write operations are carried out on the file handle, the system requires the developer to pass in the instance containing Unicode characters instead of the byte instance containing binary data.
resolvent:
Use binary write mode (“WB”) to open the file to be operated, instead of using character write mode (“W”) as before.
The method of adapting both Python 3 and python 2 is as follows
with open('python3/rndom.bin','wb') as f:
f.write(os.urandom(10))There is a similar problem when the file reads data. The solution to this problem is similar: open the file in ‘RB’ mode (binary mode) instead of ‘R’ mode.
Reproduced in: https://www.cnblogs.com/circleyuan/p/10350202.html
When running rake DB: migrate, you sometimes find an error in rake abort. Rake says that a table already exists, so it can’t do the work of this migrate. This table does exist, so how can rake skip this table or force it to be overridden?There is one area that needs to be modified:
Original migrate file:
Ruby code
Modified migrate file:
Ruby code
Do you see that in create_ In the parameter of table, add: force = & gt; True.
Wireshark is a powerful packet capture analysis tool. When it is first used on win7/10 64 bit system, unexpected situations may occur. The NPF driver isn’t running. This may be because WinPcap driver is not installed or WinPcap option is not selected when WinPcap is installed.
resolvent:
3. None of the above two situations can be solved. First, you need to confirm whether the NPF service has been installed in the system correctly. First, you need to confirm whether the npf.sys file exists in the folder C: windows?System32?Drivers. If the file does not exist, please re install WinPcap. If the file exists, then run CMD (win7/Vista user needs to press start, input CMD search, right-click the icon of cmd.exe in the search program results, and select run as administrator.
3.1 enter the command to query whether the NPF service is installed
C:\Windows\system32> sc qc npf
[SC] QueryServiceConfig SUCCESS
SERVICE_ NAME: npf
TYPE : 1 KERNEL_ DRIVER
START_ TYPE : 2 AUTO_ START
ERROR_ CONTROL : 1 NORMAL
BINARY_ PATH_ NAME : system32\drivers\npf.sys
LOAD_ ORDER_ GROUP :
TAG : 0
DISPLAY_ NAME : NetGroup Packet Filter Driver
DEPENDENCIES :
SERVICE_ START_ Name:
with the above results, the output is normal. If not, re install WinPcap and try again.
3.2 start NPF service manually:
C:\Windows\system32> SC start NPF
if there is no error prompt, Wireshark can be used normally.
3.3 if start in the query result of NPF service_ The value of type is not auto_ If you want to start, you don’t want to run the NPF driver manually every time. You can use the following command to change the NPF service to start automatically.
C:\Windows\system32> sc config npf start= auto
The source text of the post is from the website
and http://blog.sina.com.cn/s/blog_ 718ccdb90102uzqr.html
The processing method of “the NPF driver isn’t running. You may have trouble capturing or listing interfaces (as shown)” appears in Wireshark packet capturing tool
First of all, you have to make sure that you have installed WinPcap (it’s better to download the latest version: official download, which seems to be unable to be opened by the official, and it can also be downloaded by the Chinese Army)
a. If you are using Linux or Ubuntu, please use & gt$ The Su administrator command switches to the account with the highest authority, and then enters the command: “net start NPF” (if not, find a similar command yourself). b. If you are using Windows XP/me, please use the administrator account to log in, open CMD, and enter the command: “net start NPF”. You will be prompted to open the driver service successfully. c. If you are using Windows Vista or windows 7 that I tried out, please find the file cmd.exe under “C::?Windows?System32”, right-click and select “run as administrator”, and then enter the command “net start NPF” in the command line mode to successfully open the NPF driver. It should be that the npf.sys file I found earlier has been opened.
Finally, turn on Wireshark again, and “bingo” will work normally.
See