可以以各种形式指定项目的依赖项，取决于依赖项的类型以及安装项目可能需要的可选约束
| 编写规范 | 允许的版本范围 |
|---|---|
| ^1.2.3 | >=1.2.3 <2.0.0 |
| ^1.2 | >=1.2.0 <2.0.0 |
| ^1 | >=1.0.0 <2.0.0 |
| ^0.2.3 | >=0.2.3 <0.3.0 |
| ^0.0.3 | >=0.0.3 <0.0.4 |
| ^0.0 | >=0.0.0 <0.1.0 |
| ^0 | >=0.0.0 <1.0.0 |
| 编写规范 | 允许的版本范围 |
|---|---|
| ~1.2.3 | >=1.2.3 <1.3.0 |
| ~1.2 | >=1.2.0 <1.3.0 |
| ~1 | >=1.0.0 <2.0.0 |
和上面的 ^ 差不多，不过这个是次要版本，以第二个数字为基准
有点像万能匹配符，写在哪里都可以
| 编写规范 | 允许的版本范围 |
|---|---|
| * | >=0.0.0 |
| 1.* | >=1.0.0 <2.0.0 |
| 1.2.* | >=1.2.0 <1.3.0 |
就常规的＞、＜ 符号了
>= 1.2.0 > 1 < 2 != 1.2.3
确定的版本号或范围
>= 1.2，< 1.5
可以指定依赖项的 git 仓库地址
[tool.poetry.dependencies]
requests = { git = "https://github.com/requests/requests.git" }
默认会拉 git 仓库的 master 分支
也可以指定 branch、commit hash、tag
[tool.poetry.dependencies]
# Get the latest revision on the branch named "next"
requests = { git = "https://github.com/kennethreitz/requests.git", branch = "next" }
# Get a revision by its commit hash
flask = { git = "https://github.com/pallets/flask.git", rev = "38eb5d3b" }
# Get a revision by its tag
numpy = { git = "https://github.com/numpy/numpy.git", tag = "v0.13.2" }
如果依赖项位于本地目录，可以用 path
[tool.poetry.dependencies]
# directory
my-package = { path = "../my-package/", develop = false }
# file
my-package = { path = "../my-package/dist/my-package-0.1.0.tar.gz" }
如果依赖远程仓库的文件，可以用 url
[tool.poetry.dependencies]
# directory
my-package = { url = "https://example.com/my-package-0.1.0.tar.gz" }
可以通过 poetry add 来添加 url
poetry add https://example.com/my-package-0.1.0.tar.gz
指定仅应该以特定 Python 版本安装依赖项
[tool.poetry.dependencies]
pathlib2 = { version = "^2.2", python = "~2.7" }
[tool.poetry.dependencies]
pathlib2 = { version = "^2.2", python = "~2.7 || ^3.2" }
假设依赖包
版本小于等于 1.9 的时候，只能和 Python 2.7 到 Python 2.9 版本兼容
版本大于 2.0 的时候，只能和 Python 3.4 + 版本兼容
[tool.poetry.dependencies]
foo = [
{version = "<=1.9", python = "^2.7"},
{version = "^2.0", python = "^3.4"}
]
感觉比较少用，暂时不展开详解
[tool.poetry.dependencies]
pathlib2 = { version = "^2.2", markers = "python_version ~= '2.7' or sys_platform == 'win32'" }
markers 官方文档：https://www.python.org/dev/peps/pep-0508/#environment-markers
当某个依赖项需要添加很多属性的时候，可读性就很差，如下
[tool.poetry.dev-dependencies]
black = {version = "19.10b0", allow-prereleases = true, python = "^3.6", markers = "platform_python_implementation == 'CPython'"}
使用新的语法格式
[tool.poetry.dev-dependencies.black] version = "19.10b0" allow-prereleases = true python = "^3.6" markers = "platform_python_implementation == 'CPython'"
依赖项的约束完全一样，只不过变成一行一个约束属性，可读性更强
