$ pipenv
Usage: pipenv [OPTIONS] COMMAND [ARGS]...

Options:
 --where  显示项目文件所在路径
 --venv  显示虚拟环境实际文件所在路径
 --py  显示虚拟环境Python解释器所在路径
 --envs  显示虚拟环境的选项变量
 --rm  删除虚拟环境
 --bare  最小化输出
 --completion 完整输出
 --man  显示帮助页面
 --three / --two 使用Python 3/2创建虚拟环境（注意本机已安装的Python版本）
 --python TEXT 指定某个Python版本作为虚拟环境的安装源
 --site-packages 附带安装原Python解释器中的第三方库
 --jumbotron An easter egg, effectively.
 --version 版本信息
 -h, --help 帮助信息

Commands:
 check 检查安全漏洞
 graph 显示当前依赖关系图信息
 install 安装虚拟环境或者第三方库
 lock 锁定并生成Pipfile.lock文件
 open 在编辑器中查看一个库
 run 在虚拟环境中运行命令
 shell 进入虚拟环境
 uninstall 卸载一个库
 update 卸载当前所有的包，并安装它们的最新版本

import django
print(django.get_version())

Usage: pipenv [OPTIONS] COMMAND [ARGS]...

Options:
 --update  Update Pipenv & pip to latest.
 --where  Output project home information.
 --venv  Output virtualenv information.
 --py  Output Python interpreter information.
 --envs  Output Environment Variable options.
 --rm  Remove the virtualenv.
 --bare  Minimal output.
 --completion Output completion (to be eval'd).
 --man  Display manpage.
 --three / --two Use Python 3/2 when creating virtualenv.
 --python TEXT Specify which version of Python virtualenv should use.
 --site-packages Enable site-packages for the virtualenv.
 --jumbotron An easter egg, effectively.
 --version Show the version and exit.
 -h, --help Show this message and exit.

Usage Examples:
 Create a new project using Python 3.6, specifically:
 $ pipenv --python 3.6

 Install all dependencies for a project (including dev):
 $ pipenv install --dev

 Create a lockfile containing pre-releases:
 $ pipenv lock --pre

 Show a graph of your installed dependencies:
 $ pipenv graph

 Check your installed dependencies for security vulnerabilities:
 $ pipenv check

 Install a local setup.py into your virtual environment/Pipfile:
 $ pipenv install -e .

Commands:
 check Checks for security vulnerabilities and against PEP 508 markers
  provided in Pipfile.
 graph Displays currently–installed dependency graph information.
 install Installs provided packages and adds them to Pipfile, or (if none
  is given), installs all packages.
 lock Generates Pipfile.lock.
 open View a given module in your editor.
 run Spawns a command installed into the virtualenv.
 shell Spawns a shell within the virtualenv.
 uninstall Un-installs a provided package and removes it from Pipfile.
 update Uninstalls all packages, and re-installs package(s) in [packages]
  to latest compatible versions.

$ pipenv install --python 3
$ pipenv install --python 3.6
$ pipenv install --python 2.7.14

$ cat Pipfile

[[source]]
url = "https://pypi.org/simple"
verify_ssl = true
name = "pypi"

[packages]
"urllib3" = "*"

[dev-packages]

[requires]
python_version = "3.6"

$ Pipfile.lock
{
 "_meta": {
 "hash": {
  "sha256": "af58f3510cb613d4d9241128f9a0ceb9bb936ad907543e23ad8317011dcb6715"
 },
 "pipfile-spec": 6,
 "requires": {
  "python_version": "3.6"
 },
 "sources": [
  {
  "name": "pypi",
  "url": "https://pypi.org/simple",
  "verify_ssl": true
  }
 ]
 },
 "default": {  
  "urllib3": {
  "hashes": [
  "sha256:a68ac5e15e76e7e5dd2b8f94007233e01effe3e50e8daddf69acfd81cb686baf",
  "sha256:b5725a0bd4ba422ab0e66e89e030c806576753ea3ee08554382c14e685d117b5"
  ],
  "index": "pypi",
  "version": "==1.23"
 }
 },
 "develop": {}
}

$ pipenv --venv
/Users/kennethreitz/.local/share/virtualenvs/test-Skyy4vre

$ pipenv --py
/Users/kennethreitz/.local/share/virtualenvs/test-Skyy4vre/bin/python

$ pipenv install django --dev
Installing pytest...
...
Adding pytest to Pipfile's [dev-packages]...

$ pipenv graph
requests==2.18.4
 - certifi [required: >=2017.4.17, installed: 2017.7.27.1]
 - chardet [required: >=3.0.2,<3.1.0, installed: 3.0.4]
 - idna [required: >=2.5,<2.7, installed: 2.6]
 - urllib3 [required: <1.23,>=1.21.1, installed: 1.22]

$ pipenv lock
Assuring all dependencies from Pipfile are installed...
Locking [dev-packages] dependencies...
Locking [packages] dependencies...
Note: your project now has only default [packages] installed.
To install [dev-packages], run: $ pipenv install --dev

$ pipenv uninstall urllib3 
或者
$ pipenv uninstall --all

$ pipenv update urllib3
$ pipenv update # 更新所有安装包

$ pipenv check
Checking PEP 508 requirements…
Passed!
Checking installed package safety…
All good!

[[source]]
name = "pypi"
url = "https://pypi.tuna.tsinghua.edu.cn/simple/"
verify_ssl = true

[dev-packages]

[packages]
requests = "*"
paho-mqtt = "*"
pymongo = "*"
can = "*"
crypto = "*"
gvent = "*"
gevent = "*"

[requires]
python_version = "3.7"