解决 python pip install安装速度慢| You are using pip version 19.2.3, however version 20.0.2 is available.
解决升级问题：
C:\WINDOWS\system32>python -m pip install --upgrade pip -i https://pypi.douban.com/simple
Looking in indexes: https://pypi.douban.com/simple
Collecting pip
Downloading https://pypi.doubanio.com/packages/54/0c/d01aa759fdc501a58f431eb594a17495f15b88da142ce14b5845662c13f3/pip-20.0.2-py2.py3-none-any.whl (1.4MB)
|████████████████████████████████| 1.4MB 177kB/s
Installing collected packages: pip
Found existing installation: pip 19.2.3
Uninstalling pip-19.2.3:
Successfully uninstalled pip-19.2.3
Successfully installed pip-20.0.2
找到个更加优秀的：
命令：
pip install keras -i http://pypi.douban.com/simple --trusted-host pypi.douban.com（其中的keras是你需要下载的，根据自己需求自行更改）
结果：
（不用理会让升级的警告！）
命令：
pip install -i https://pypi.tuna.tsinghua.edu.cn/simple scrapy截图：
通过：
pip help install查看到：
C:\Users\HWP>pip help install
Usage:
pip install [options] [package-index-options] ...
pip install [options] -r [package-index-options] ...
pip install [options] [-e] ...
pip install [options] [-e] ...
pip install [options] ...
Description:
Install packages from:
- PyPI (and other indexes) using requirement specifiers.
- VCS project urls.
- Local project directories.
- Local or remote source archives.
pip also supports installing from "requirements files," which provide
an easy way to specify a whole environment to be installed.
Install Options:
-r, --requirement Install from the given requirements file. This option can be used multiple times.
-c, --constraint Constrain versions using the given constraints file. This option can be used multiple
times.
--no-deps Don't install package dependencies.
--pre Include pre-release and development versions. By default, pip only finds stable
versions.
-e, --editable Install a project in editable mode (i.e. setuptools "develop mode") from a local project
path or a VCS url.
-t, --target Install packages into . By default this will not replace existing files/folders in
. Use --upgrade to replace existing packages in with new versions.
--platform Only use wheels compatible with . Defaults to the platform of the running
system.
--python-version
The Python interpreter version to use for wheel and "Requires-Python" compatibility
checks. Defaults to a version derived from the running interpreter. The version can be
specified using up to three dot-separated integers (e.g. "3" for 3.0.0, "3.7" for 3.7.0,
or "3.7.3"). A major-minor version can also be given as a string without dots (e.g. "37"
for 3.7.0).
--implementation
Only use wheels compatible with Python implementation , e.g. 'pp', 'jy',
'cp', or 'ip'. If not specified, then the current interpreter implementation is used.
Use 'py' to force implementation-agnostic wheels.
--abi Only use wheels compatible with Python abi , e.g. 'pypy_41'. If not specified,
then the current interpreter abi tag is used. Generally you will need to specify
--implementation, --platform, and --python-version when using this option.
--user Install to the Python user install directory for your platform. Typically ~/.local/, or
%APPDATA%\Python on Windows. (See the Python documentation for site.USER_BASE for full
details.)
--root Install everything relative to this alternate root directory.
--prefix Installation prefix where lib, bin and other top-level folders are placed
-b, --build Directory to unpack packages into and build in. Note that an initial build still takes
place in a temporary directory. The location of temporary directories can be controlled
by setting the TMPDIR environment variable (TEMP on Windows) appropriately. When passed,
build directories are not cleaned in case of failures.
--src Directory to check out editable projects into. The default in a virtualenv is "/src". The default for global installs is "/src".
-U, --upgrade Upgrade all specified packages to the newest available version. The handling of
dependencies depends on the upgrade-strategy used.
--upgrade-strategy
Determines how dependency upgrading should be handled [default: only-if-needed]. "eager"
- dependencies are upgraded regardless of whether the currently installed version
satisfies the requirements of the upgraded package(s). "only-if-needed" - are upgraded
only when they do not satisfy the requirements of the upgraded package(s).
--force-reinstall Reinstall all packages even if they are already up-to-date.
-I, --ignore-installed Ignore the installed packages (reinstalling instead).
--ignore-requires-python Ignore the Requires-Python information.
--no-build-isolation Disable isolation when building a modern source distribution. Build dependencies
specified by PEP 518 must be already installed if this option is used.
--use-pep517 Use PEP 517 for building source distributions (use --no-use-pep517 to force legacy
behaviour).
--install-option Extra arguments to be supplied to the setup.py install command (use like --install-
option="--install-scripts=/usr/local/bin"). Use multiple --install-option options to
pass multiple options to setup.py install. If you are using an option with a directory
path, be sure to use absolute path.
--global-option Extra global options to be supplied to the setup.py call before the install command.
--compile Compile Python source files to bytecode
--no-compile Do not compile Python source files to bytecode
--no-warn-script-location Do not warn when installing scripts outside PATH
--no-warn-conflicts Do not warn about broken dependencies
--no-binary
Do not use binary packages. Can be supplied multiple times, and each time adds to the
existing value. Accepts either :all: to disable all binary packages, :none: to empty the
set, or one or more package names with commas between them. Note that some packages are
tricky to compile and may fail to install when this option is used on them.
--only-binary
Do not use source packages. Can be supplied multiple times, and each time adds to the
existing value. Accepts either :all: to disable all source packages, :none: to empty the
set, or one or more package names with commas between them. Packages without binary
distributions will fail to install when this option is used on them.
--prefer-binary Prefer older binary packages over newer source packages.
--no-clean Don't clean up build directories.
--require-hashes Require a hash to check each requirement against, for repeatable installs. This option
is implied when any package in a requirements file has a --hash option.
--progress-bar
Specify type of progress to be displayed [off|on|ascii|pretty|emoji] (default: on)
Package Index Options:
-i, --index-url Base URL of the Python Package Index (default https://pypi.org/simple). This should
point to a repository compliant with PEP 503 (the simple repository API) or a local
directory laid out in the same format.
--extra-index-url Extra URLs of package indexes to use in addition to --index-url. Should follow the same
rules as --index-url.
--no-index Ignore package index (only looking at --find-links URLs instead).
-f, --find-links If a url or path to an html file, then parse for links to archives. If a local path or
file:// url that's a directory, then look for archives in the directory listing.
General Options:
-h, --help Show help.
--isolated Run pip in an isolated mode, ignoring environment variables and user configuration.
-v, --verbose Give more output. Option is additive, and can be used up to 3 times.
-V, --version Show version and exit.
-q, --quiet Give less output. Option is additive, and can be used up to 3 times (corresponding to
WARNING, ERROR, and CRITICAL logging levels).
--log Path to a verbose appending log.
--proxy Specify a proxy in the form [user:passwd@]proxy.server:port.
--retries Maximum number of retries each connection should attempt (default 5 times).
--timeout Set the socket timeout (default 15 seconds).
--exists-action Default action when a path already exists: (s)witch, (i)gnore, (w)ipe, (b)ackup,
(a)bort.
--trusted-host Mark this host as trusted, even though it does not have valid or any HTTPS.
--cert Path to alternate CA bundle.
--client-cert Path to SSL client certificate, a single file containing the private key and the
certificate in PEM format.
--cache-dir Store the cache data in .
--no-cache-dir Disable the cache.
--disable-pip-version-check
Don't periodically check PyPI to determine whether a new version of pip is available for
download. Implied with --no-index.
--no-color Suppress colored output
C:\Users\HWP> 注意：
