search
HomeBackend DevelopmentPython TutorialWhy NameResolutionError(self.host, self, e) from e and how to solve it

Why NameResolutionError(self.host, self, e) from e and how to solve it

Mar 01, 2024 pm 01:20 PM
pythonError handlingurldnsselfurllibBackend Developmentdns resolution failedurllib3

为什么NameResolutionError(self.host, self, e) from e,怎么解决

The reason for the error

NameResolutionError(self.host, self, e) from e is the exception type in the urllib3 library, The cause of this error is a DNS resolution failure, that is, the hostname or IP address that was attempted to be resolved could not be found. This may be caused by the entered URL address being incorrect, or the DNSserver being temporarily unavailable.

How to solve

There may be several ways to solve this error:

Check whether the entered URL address is correct and make sure it is accessible

Make sure the DNS server is available, you can try using the "ping" command on the command line to Test whether the DNS server is available

Try using the IP address instead of the hostname to access the website

If you are in a proxy environment, check whether the proxy configuration is correct.

Check the network connection to make sure the localhost can access the Internet.

Usage example

Yes, the following is a sample code that uses the urllib3 library to access the URL and handle the NameResolutionError exception:

import urllib3

Http = urllib3.PoolManager()

try:
response = http.request('GET', 'http://example.com')
print(response.data)
except urllib3.exceptions.NewConnectionError as e:
print("Name resolution error: ", e)

In this example, we use the PoolManager() method of the urllib3 library to create an HTTP connection pool, and then use the request() method to issue a GET request. If a NameResolutionError exception occurs, it will be caught and error information printed.

Note: When using http.request(), if the entered url is incorrect or inaccessible, errors such as MaxRetryError and NewConnectionError will be thrown, and corresponding handling is required.

The above is the detailed content of Why NameResolutionError(self.host, self, e) from e and how to solve it. For more information, please follow other related articles on the PHP Chinese website!

Statement
This article is reproduced at:编程网. If there is any infringement, please contact admin@php.cn delete
What data types can be stored in a Python array?What data types can be stored in a Python array?Apr 27, 2025 am 12:11 AM

Pythonlistscanstoreanydatatype,arraymodulearraysstoreonetype,andNumPyarraysarefornumericalcomputations.1)Listsareversatilebutlessmemory-efficient.2)Arraymodulearraysarememory-efficientforhomogeneousdata.3)NumPyarraysareoptimizedforperformanceinscient

What happens if you try to store a value of the wrong data type in a Python array?What happens if you try to store a value of the wrong data type in a Python array?Apr 27, 2025 am 12:10 AM

WhenyouattempttostoreavalueofthewrongdatatypeinaPythonarray,you'llencounteraTypeError.Thisisduetothearraymodule'sstricttypeenforcement,whichrequiresallelementstobeofthesametypeasspecifiedbythetypecode.Forperformancereasons,arraysaremoreefficientthanl

Which is part of the Python standard library: lists or arrays?Which is part of the Python standard library: lists or arrays?Apr 27, 2025 am 12:03 AM

Pythonlistsarepartofthestandardlibrary,whilearraysarenot.Listsarebuilt-in,versatile,andusedforstoringcollections,whereasarraysareprovidedbythearraymoduleandlesscommonlyusedduetolimitedfunctionality.

What should you check if the script executes with the wrong Python version?What should you check if the script executes with the wrong Python version?Apr 27, 2025 am 12:01 AM

ThescriptisrunningwiththewrongPythonversionduetoincorrectdefaultinterpretersettings.Tofixthis:1)CheckthedefaultPythonversionusingpython--versionorpython3--version.2)Usevirtualenvironmentsbycreatingonewithpython3.9-mvenvmyenv,activatingit,andverifying

What are some common operations that can be performed on Python arrays?What are some common operations that can be performed on Python arrays?Apr 26, 2025 am 12:22 AM

Pythonarrayssupportvariousoperations:1)Slicingextractssubsets,2)Appending/Extendingaddselements,3)Insertingplaceselementsatspecificpositions,4)Removingdeleteselements,5)Sorting/Reversingchangesorder,and6)Listcomprehensionscreatenewlistsbasedonexistin

In what types of applications are NumPy arrays commonly used?In what types of applications are NumPy arrays commonly used?Apr 26, 2025 am 12:13 AM

NumPyarraysareessentialforapplicationsrequiringefficientnumericalcomputationsanddatamanipulation.Theyarecrucialindatascience,machinelearning,physics,engineering,andfinanceduetotheirabilitytohandlelarge-scaledataefficiently.Forexample,infinancialanaly

When would you choose to use an array over a list in Python?When would you choose to use an array over a list in Python?Apr 26, 2025 am 12:12 AM

Useanarray.arrayoveralistinPythonwhendealingwithhomogeneousdata,performance-criticalcode,orinterfacingwithCcode.1)HomogeneousData:Arrayssavememorywithtypedelements.2)Performance-CriticalCode:Arraysofferbetterperformancefornumericaloperations.3)Interf

Are all list operations supported by arrays, and vice versa? Why or why not?Are all list operations supported by arrays, and vice versa? Why or why not?Apr 26, 2025 am 12:05 AM

No,notalllistoperationsaresupportedbyarrays,andviceversa.1)Arraysdonotsupportdynamicoperationslikeappendorinsertwithoutresizing,whichimpactsperformance.2)Listsdonotguaranteeconstanttimecomplexityfordirectaccesslikearraysdo.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

DVWA

DVWA

Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software