Python 实用宝典

Question 1

Using pip install for any module apparently on my Ubuntu 16.04 system with python 2.7.11+ throws this error:

TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'

What is wrong with pip? How could I reinstall it, if necessary?

Update: Full traceback is below

sunny@sunny:~$ pip install requests
Collecting requests
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 page in self._get_pages(url_locations, project_name):
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 545, in _get_pages
    page = self._get_page(location)
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 648, in _get_page
    return HTMLPage.get_page(link, session=self.session)
  File "/usr/lib/python2.7/dist-packages/pip/index.py", line 757, in get_page
    "Cache-Control": "max-age=600",
  File "/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/sessions.py", line 480, in get
    return self.request('GET', url, **kwargs)
  File "/usr/lib/python2.7/dist-packages/pip/download.py", line 378, in request
    return super(PipSession, self).request(method, url, *args, **kwargs)
  File "/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/sessions.py", line 468, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/sessions.py", line 576, in send
    r = adapter.send(request, **kwargs)
  File "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/adapter.py", line 46, in send
    resp = super(CacheControlAdapter, self).send(request, **kw)
  File "/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/adapters.py", line 376, in send
    timeout=timeout
  File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/connectionpool.py", line 610, in urlopen
    _stacktrace=sys.exc_info()[2])
  File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/util/retry.py", line 228, in increment
    total -= 1
TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'

Question 2

Ubuntu comes with a version of PIP from precambrian and that’s how you have to upgrade it if you do not want to spend hours and hours debugging pip related issues.

apt-get remove python-pip python3-pip
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
python3 get-pip.py

As you observed I included information for both Python 2.x and 3.x

Question 3

If you are behind a proxy, you must do some extra configuration steps before starting the installation. You must set the environment variable http_proxy to the proxy address. Using bash this is accomplished with the command

export http_proxy="http://user:pass@my.site:port/"

You can also provide the

--proxy=[user:pass@]url:port

parameter to pip. The [user:pass@] portion is optional.

Question 4

Updating setuptools has worked out fine for me.

sudo pip install --upgrade setuptools

Question 5

First of all, this problem exists because of network issues, and uninstalling and re-installing everything won’t be of much help. Probably you are behind proxy, and in that case you need to set proxy.

But in my case, I was facing the problem because I wasn’t behind proxy. Generally, I work behind proxy, but when working from home, I set the proxy to None in Network settings.

But I was still getting the same errors even after removing the proxy settings.

So, when I did type

env | grep proxy

I found something like this :

http_proxy=http://127.0.0.1:1234/

And this was the reason I was still getting the very same error, even when I thought I had removed the proxy settings.

To unset this proxy, type

unset http_proxy

Follow the same approach for all the other entries, such as https_proxy.

Question 6

What happens here is that the the vendored versions of request/urllib3 clash when imported in two different places (same code, but different names). If you then have a network error, it doesn’t retry to get the wheel, but fails with the above error. See here for a deeper dive into this error.

For the solution with system pip, see above.

If you have this problem in a virtualenv built by python -m venv (which still copies the wheels from /usr/share/python-wheels, even if you have pip installed separately), the easiest way to “fix” it seems to be:

create the virtualenv: /usr/bin/python3.6 -m venv ...
install requests into the environment (this might raise the above error): <venv>/bin/pip install requests
remove the copied versions of requests which would be used by pip: rm <venv>/share/python-wheels/{requests,chardet,urllib3}-*.whl

Now a <venv>/bin/pip uses the installed version of requests which has urllib3 vendored.

Question 7

port 443 is not open, just allow custom tcp port 443 if on AWS else open the port 443 for the outbound connections …

Question 8

Just upgrade pip worked for me:

pip install --upgrade pip

Question 9

I have the same problem when installing a RaspberryPI TFT from Adafruit with pitft.sh / adafruit-pitft.sh.

I am not happy about coding-styles with errors from somewhere to be interpreted somehow – as could be seen by the previous answers.

Remark: The type error exception of retry.py is obviously a bug, caused by an unappropriate assignement and calculation of an instance of the class Reply to an int with the default value of 10 – somewhere in the code… Should be fixed either by adding an inplace-operator, or fixing the erroneous assignment.

So tried to analyse and patch the error itself first. The actual error in my case case is the same – retry.py called by pip.

The installation script adafruit-pitft.sh / pitft.sh tries to apply urllib3 which itself tries to install nested dependencies by pip, so the same error.

adafruit-pitft.sh # or pitft.sh

…

_stacktrace=sys.exc_info()[2]) File “/usr/share/python-wheels/urllib3-1.13.1-py2.py3 none-any.whl/urllib3/util/retry.py”, line 228, in increment

total -= 1

TypeError: unsupported operand type(s) for -=: ‘Retry’ and ‘int’

For the current distribution(based on debian-9.6.0/stretch):

File “/usr/share/python-wheels/urllib3-1.19.1-py2.py3-none-any.whl/urllib3/util/retry.py”, line 315, in increment

total -= 1

TypeError: unsupported operand type(s) for -=: ‘Retry’ and ‘int’

The following – dirty *:) – patch enables a sounding error trace:

# File: retry.py - in *def increment(self, ..* about line 315
# original: total = self.total

# patch: quick-and-dirty-fix
# START:
if isinstance(self.total, Retry):
    self.total = self.total.total

if type(self.total) is not int:
    self.total = 2 # default is 10
# END:

# continue with original:
total = self.total

if total is not None:
    total -= 1

connect = self.connect
read = self.read
redirect = self.redirect
cause = 'unknown'
status = None
redirect_location = None

if error and self._is_connection_error(error):
    # Connect retry?
    if connect is False:
        raise six.reraise(type(error), error, _stacktrace)
    elif connect is not None:
        connect -= 1

The sounding output with the temporary patch is(displayed twice…?):

Retrying (Retry(total=1, connect=None, read=None, redirect=None)) after connection broken by ‘ConnectTimeoutError(<requests.packages.urllib3.connection.VerifiedHTTPSConnection object at/

Retrying (Retry(total=0, connect=None, read=None, redirect=None)) after connection broken by ‘ConnectTimeoutError(<requests.packages.urllib3.connection.VerifiedHTTPSConnection object at/

Could not find a version that satisfies the requirement evdev (from versions: )

No matching distribution found for evdev

WARNING : Pip failed to install software!

So in my case actually two things cause the error, this may vary in other environments:

Missing evdev => try to install
Failed to connect a repo/dist containing evdev in order to download. => finally give it up

My installation environment is offline from an internal debian+raspbian mirror, thus do not want to set the proxy…

So I proceeded by manual installation of the missing component evdev:

download evdev from PyPI(or e.g. from github.com):

https://pypi.org/project/evdev/

https://files.pythonhosted.org/packages/7e/53/374b82dd2ccec240b7388c65075391147524255466651a14340615aabb5f/evdev-1.1.2.tar.gz
Unpack and install manually as root user – for all local accounts, so detected as installed:

sudo su –

tar xf evdev-1.1.2.tar.gz

cd evdev-1.1.2

python setup.py install
Call install script again:

adafruit-pitft.sh # or pitft.sh

…Answer dialogues…

…that’s it.

If you proceed online by direct PyPI access:

check your routing + firewall for access to pypi.org
set a proxy if required (http_proxy/https_proxy)

And it works..

Hope this helps in other cases too.

Arno-Can Uestuensoez

———————————————-

See also: issue – 35334: https://bugs.python.org/issue35334

———————————————-

See now also: issue – 1486: https://github.com/urllib3/urllib3/issues/1486

for file: https://github.com/urllib3/urllib3/blob/master/src/urllib3/util/retry.py

Question 10

check for network issues, to bypass the exception case code

In my case, I was using a custom index, that index had no route and such would trigger the exception case code. The exception case bug still exists and still masks the real issue, however I was able to work around this by testing the connectivity with other tools such as nc -vzw1 myindex.example.org 443 and retrying when the network was up.

Question 11

I was facing similar issue while trying to install awscli tool on ec2 instance. I changed security group to allow port 443 inbound and outbound access and that solved the issue for me.

Question 12

I got this error when I was trying to create a virtualenv with command virtualenv myVirtualEnv. I just added a sudo before the command; it solved everything.

Question 13

Solution:
1. sudo apt remove python-pip
2. pip3 install pip (or install pip by get-pip.py)

Why:
This error occurred on pip 8.0.1 which installed by apt-get. And happened only when your network is unstable.

If you have a pip installed with apt, it hides the pip you installed by other ways, so you should remove the apt one first.

I disconnected the network and tested 8.0.1, 9.0.3, 10.x the 3 versions installed with pip3 or get-pip.py, no error occurred. So, I think only the apt version of pip 8.0.1 has that bug, the others is ok.

Question 14

In my case, i had opened Pycharm in sudo mode, and was running pip install nltk in pycharm terminal which showed this error. running with sudo pip install solves the error.

Question 15

I also had this issue. Initially, a proxy was set and work fine. Then I connected to a network where it doesn’t go through a proxy. After unsetting proxy pip again get works.

unset http_proxy; unset http_prox;  unset HTTP_PROXY; unset HTTPS_PROXY

Question 16

Bizarrely if I remove the proxy from the environment and add it to the command line it works for me. For example to upgrade pip itself:

env http_proxy= https_proxy= pip install pip --upgrade --proxy 'http://proxy-url:80'

My issue was having the proxy in the environment. It seems that pip only honors the one in argument.

Question 17

This is the working solution to this problem I found.

sudo apt-get clean
cd /var/lib/apt
sudo mv lists lists.old
sudo mkdir -p lists/partial
sudo apt-get clean
sudo apt-get update

Question 18

For myself, it turns out that wlan0 was down, which resulted in me being unable to connect out. So, ensuring that wlan0 was up, allowed pip / pip3 to work without issue.

Question 19

I tried the solution answered above:

apt-get remove python-pip python3-pip
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
python3 get-pip.py

When I tried

python get-pip.py 
python3 get-pip.py

I got this message

 Could not install packages due to an EnvironmentError:
[Errno 13] Permission denied: /usr/bin/pip3 Consider using the --user
 option or check the permissions.

I did the following and it works

python3 -m venv env
source ./env/bin/activate
Sudo apt-get update 
apt-get remove python-pip python3-pip
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
python3 get-pip.py
pip3 install pip
sudo easy_install pip
pip install --upgrade pip

Python 实用宝典

Python PIP安装会引发TypeError：-=：’Retry’和’int’不受支持的操作数类型

问题：Python PIP安装会引发TypeError：-=：’Retry’和’int’不受支持的操作数类型

回答 0

回答 1

回答 2

回答 3

回答 4

回答 5

回答 6

回答 7

———————————————-

———————————————-

———————————————-

———————————————-

回答 8

检查网络问题，绕过异常案例代码

check for network issues, to bypass the exception case code

回答 9

回答 10

回答 11

回答 12

回答 13

回答 14

回答 15

回答 16

回答 17

有趣好用的Python教程