# 创建conda环境
$ mamba env create -f env.yml
# 根据需要更新conda环境
$ mamba env update -n current_project --file env.yml
# $ mamba env update -n current_project --file env.mac.yml

# 激活conda环境
$ conda activate current_project

# 用于本地开发安装
$ pip install -e .

# 示例YAML文件
name: current_project
channels:
  - pytorch
  - conda-forge  
  - fastai
dependencies:  
  - python>=3.10
 # 实用工具
 # -------------------------------------------------------------------------
  - tqdm
  - rich
  - typer
  # Jupyter Notebook
  # -------------------------------------------------------------------------
  - conda-forge::notebook
  - conda-forge::ipykernel
  - conda-forge::ipywidgets
  - conda-forge::jupyter_contrib_nbextensions
  
  # nbdev
  # -------------------------------------------------------------------------
  - fastai::nbdev>=2.3.12
  # PyTorch &深度学习
  # -------------------------------------------------------------------------
  - pytorch>=2
  # 注意：如果使用支持CUDA的GPU，添加pytorch-cuda。如果您使用的是Apple Silicon，则需要删除此项
  # - pytorch::pytorch-cuda
  - conda-forge::pytorch-lightning
  # 绘图
  # -------------------------------------------------------------------------
  - conda-forge::matplotlib
  - conda-forge::seaborn
  
  # 数据整理
  # -------------------------------------------------------------------------
  - conda-forge::scikit
<details>
<summary>英文:</summary>
**NOTE**: you can start at [Problem formulation][problem formulation]. The motivation section just explains how I found myself asking this.
# Motivation
I use and love [nbdev]. It makes developing a python package iteratively as easy as it gets. Especially, as I generally do this along side a project which uses said package. Does this question require knowledge of [nbdev]? **no**. It only motivates why I am asking. Normally when I create a new [nbdev] project (`nbdev_new`), I get a `settings.ini` file and `setup.py` file. In order to keep working on different packages / projects simple, I will immediately create a [conda environment file][conda yml] `env.yml` for the project (see `Files &gt; Example Conda File` [maybe this link works][example env file]). 
I know that the environment one develops a package in is **NOT** necessarily the minimum dependencies it requires. Further, a package&#39;s dependencies are a subset of those one may _need_ for a working on a project utilizing said package. In **MY** use case it is clear that I am double-dipping! I am *developing* the package as I _use_ it on a project. 
So for the sake of this question let&#39;s assume that the `package dependencies == project dependencies`. In other words, the `env.yml` file contains all of the `requirements` for the `setting.ini` file.
## nbdev workflow
1. make new empty repo &quot;current_project&quot; and clone it
2. `cd path/to/current_project`
3. `nbdev_new`
4. make `env.yml` file
5. create / update environment:
```sh
# create conda environment
$ mamba env create -f env.yml
# update conda environment as needed
$ mamba env update -n current_project --file env.yml
# $ mamba env update -n current_project --file env.mac.yml

# activate conda environment
$ conda activate current_project

# install for local development
$ pip install -e .

# EXAMPLE YAML FILE
name: current_project
channels:
  - pytorch
  - conda-forge  
  - fastai
dependencies:  
  - python>=3.10
 # Utilities
 # -------------------------------------------------------------------------
  - tqdm
  - rich
  - typer
  # Jupyter Notebook
  # -------------------------------------------------------------------------
  - conda-forge::notebook
  - conda-forge::ipykernel
  - conda-forge::ipywidgets
  - conda-forge::jupyter_contrib_nbextensions
  
  # nbdev
  # -------------------------------------------------------------------------
  - fastai::nbdev>=2.3.12
  # PyTorch & Deep Learning
  # -------------------------------------------------------------------------
  - pytorch>=2
  # NOTE: add pytorch-cuda if using a CUDA enabled GPU. You will need to 
  #       remove this if you are on Apple Silicon
  # - pytorch::pytorch-cuda
  - conda-forge::pytorch-lightning
  # Plotting
  # -------------------------------------------------------------------------
  - conda-forge::matplotlib
  - conda-forge::seaborn
  
  # Data Wrangling
  # -------------------------------------------------------------------------
  - conda-forge::scikit-learn
  - pandas>=2
  - numpy
  - scipy    
  # Pip / non-conda packages
  # -------------------------------------------------------------------------
  - pip
  - pip: 
    # PyTorch & Deep Learning
    # -----------------------------------------------------------------------
    - dgl

# 默认用法
$ python env_to_ini.py
# 显示未更改的包
$ python env_to_ini.py  --unchanged  
# 指定不同的环境文件
$ python env_to_ini.py  --unchanged  --file=env.mac.yml

# TODO: 改进 1：使用要排除的包的列表。
# 默认情况下，这将包括 python 和 pip。

dependencies:
  - python>=3.10
  # - ...
ignore:
  - python
  - pip
  # ...

# TODO: 改进 2：使用要重命名的包的映射。
# 默认情况下，这将包括 pytorch --> torch。
# 理想情况下，它会自动弄清楚。

dependencies:
  - python>=3.10
  # - ...
rename:
  - pytorch,torch
  # ...

# env_to_ini.py
import yaml
import configparser
from rich.console import Console
from rich.table import Table
import typer
from typing import Optional, Tuple
app = typer.Typer()
console = Console()
# NOTE: utility function to print colored text
def cprint(style: str, text: str) -> None:
    console.print(f"[{style}]{text}[/{style}]")
def has_channel(requirements_str: str) -> bool:
    return '::' in requirements_str
def extract_channel(requirements_str: str) -> Tuple[Optional[str], str]:
    channel = None
    if has_channel(requirements_str):
        channel, requirements_str = requirements_str.split('::', 1)
    return channel, requirements_str
def is_not_valid_package_char(s: str) -> bool:
    return not (s.isalnum() or s in ['-', '_', '.'])
def split_str_at_first_non_alpha(s: str) -> Tuple[str, str]:
    idx = next((
        i for i, char in enumerate(s)
        if is_not_valid_package_char(char)
    ), len(s))
    return s[:idx], s[idx:]
def split_package_version(s: str) -> Tuple[str, str]:
    # NOTE: alias for split_str_at_first_non_alpha
    return split_str_at_first_non_alpha(s)
# NOTE: this parses requirements from the settings.ini file. Thus there is one line and each package is separated by a space.
def parse_requirements(requirements_str):
    requirements = {}
    for req in requirements_str.split():
        package, version = split_package_version(req)
        requirements[package] = version
    return requirements
# NOTE: this parse depdencies form the env.yml file.
def extract_packages(dependencies):
    packages = {}
    for dep in dependencies:
        if isinstance(dep, str):
            channel, package_version = extract_channel(dep)
            package, version = split_package_version(package_version)
            # TODO: IMPROVEMENT 1: utilize a list of packages to exclude.
            #       by default this would include python and pip.
            # NOTE: we do not need to add python to the requirements
            if package == 'python':
                continue
            # NOTE: likewise we do not need pip
            elif package == 'pip':
                continue
            packages[package] = version
<details>
<summary>英文:</summary>
# Current Solution
The current solution is the file `env_to_ini.py` (see `Files &gt; env_to_ini.py` [maybe this link works][script]). 
**NOTE** this solution uses [`rich`][rich] and [`typer`][typer] to create an informative command line interface (CLI) which will show you which dependencies were added, changed, removed, or unchanged. This should make working with the script easier (especially should there be bugs in it) as it has not been extensively tested.
## How to use `env_to_ini.py`
Assumptions:
- `env.yml` or `env.mac.yml` under project root
- `settings.ini` under project root
- `env_to_ini.py` under project root
This script is provided so that if the `env.yml` (or `env.mac.yml`) file changes you can automatically update the dependencies of the `current_project` package (under `settings.ini`) to match.
```shell
# default usage
$ python env_to_ini.py
# show packages that didnt change
$ python env_to_ini.py  --unchanged  
# specify a different environment file
$ python env_to_ini.py  --unchanged  --file=env.mac.yml

# TODO: IMPROVEMENT 1: utilize a list of packages to exclude.
#       by default this would include python and pip.        

dependencies:
  - python>=3.10
  # - ...
ignore:
  - python
  - pip
  # ...

# TODO: IMPROVEMENT 2: utilize a map of packages to rename.
#       by default this would include pytorch --> torch.
#       Ideally, this would figure it out automatically.

dependencies:
  - python>=3.10
  # - ...
rename:
  - pytorch,torch
  # ...

# env_to_ini.py
import yaml
import configparser
from rich.console import Console
from rich.table import Table
import typer
from typing import Optional, Tuple
app = typer.Typer()
console = Console()
# NOTE: utility function to print colored text
def cprint(style:str, text:str) -> None:
    console.print(f"[{style}]{text}[/{style}]")
def has_channel(requirements_str:str) -> bool:
    return '::' in requirements_str
def extract_channel(requirements_str:str) -> Tuple[Optional[str], str]:
    channel = None    
    if has_channel(requirements_str):
        channel, requirements_str = requirements_str.split('::', 1)        
    return channel, requirements_str
def is_not_valid_package_char(s:str) -> bool:
    return not (s.isalnum() or s in ['-', '_', '.'])
def split_str_at_first_non_alpha(s:str) -> Tuple[str, str]:
    idx = next((
            i for i, char in enumerate(s) 
            if is_not_valid_package_char(char)
        ), len(s))
    return s[:idx], s[idx:]
def split_package_version(s:str) -> Tuple[str, str]:
    # NOTE: alias for split_str_at_first_non_alpha
    return split_str_at_first_non_alpha(s)
# NOTE: this parses requirements from the settings.ini file. Thus there is one line and each package is separated by a space.
def parse_requirements(requirements_str):
    requirements = {}
    for req in requirements_str.split():
        package, version = split_package_version(req)
        requirements[package] = version
    return requirements
# NOTE: this parse depdencies form the env.yml file.
def extract_packages(dependencies):
    packages = {}
    for dep in dependencies:
        if isinstance(dep, str):
            channel, package_version = extract_channel(dep)
            package, version = split_package_version(package_version)
            # TODO: IMPROVEMENT 1: utilize a list of packages to exclude.
            #       by default this would include python and pip.
            
            # NOTE: we do not need to add python to the requirements
            if package == 'python':
                continue
            # NOTE: likewise we do not need pip
            elif package == 'pip':
                continue
            packages[package] = version
        
        elif isinstance(dep, dict):
            for key, values in dep.items():                
                if key == 'pip':
                    for pip_dep in values:                        
                        package, version = split_package_version(pip_dep)                        
                        packages[package] = version                        
    return packages
# NOTE: check if the depdencies in the env.yml file vary from the ones in the settings.ini file.
def compare_requirements(old, new):
    added = {k: v for k, v in new.items() if k not in old}
    removed = {k: v for k, v in old.items() if k not in new}
    changed = {k: (old[k], new[k]) for k in old if k in new and old[k] != new[k]}
    remained = {k: (old[k], new[k]) for k in old if k in new and old[k] == new[k]}
    return added, removed, changed, remained
# NOTE: I like pretty terminals
def print_changes(added, removed, changed, remained):
    table = Table(title="Changes")
    table.add_column("Package", style="cyan")
    table.add_column("Old Version", style="magenta")
    table.add_column("New Version", style="green")
    table.add_column("Status", style="yellow")
    for package, version in added.items():
        table.add_row(f':package: {package}', "", version, "Added")
    for package, version in removed.items():
        table.add_row(f':package: {package}', version, "", "Removed")        
    for package, versions in changed.items():
        table.add_row(f':package: {package}', versions[0], versions[1], "Changed")
    for package, versions in remained.items():
        table.add_row(f':package: {package}', versions[0], versions[1], "Unchanged")
    console.print(table)
def requirements_to_ini(requirments:dict) -> str:
    ini = ''
    for package, version in requirments.items():
        # TODO: IMPROVEMENT 2: utilize a map of packages to rename.
        #       by default this would include pytorch --> torch.
        #       Ideally, this would figure it out automatically.
        # NOTE: this is a hack to make the env.yml file compatible with the settings.ini file
        #       since the env.yml file uses pytorch and the settings.ini file uses torch.
        #       Add more elif statements if you need to change other package names.
        if package == 'pytorch':
            package = 'torch'
        if version:
            ini += f"{package}{version} "
        else:
            ini += f"{package} "
    return ini
@app.command()
def update_requirements(
    file: Optional[str] = typer.Option(
        'env.mac.yml', 
        help="YAML file to extract the new requirements from.",
    ),
    unchanged: Optional[bool] = typer.Option(
        False,
        help="Whether to print all packages, including the ones whose versions haven't changed.",
    ),
):
    # NOTE: notice that file is `env.mac.yml` and not `env.yml`. Now with Apple Silicon I have 
    #       one env file for more common CUDA versions and one for Apple Silicon.
    
    cprint("bold cyan", f"Loading environment yaml file {file}...")
    with open(file, 'r') as f:
        env = yaml.safe_load(f)
    # NOTE: read in the current dependencies from the conda env.yml file
    cprint("bold cyan", "Extracting packages and their versions...")
    new_requirements = extract_packages(env['dependencies'])
    # NOTE: read in the previous requirements from the settings.ini file
    cprint("bold cyan", "Loading settings.ini file...")
    config = configparser.ConfigParser()
    config.read('settings.ini')
    cprint("bold cyan", "Comparing the old and new requirements...")
    old_requirements = parse_requirements(config['DEFAULT']['requirements'])
    # NOTE: check for changes
    added, removed, changed, remained = compare_requirements(old_requirements, new_requirements)
    # If --unchanged option is given, print unchanged packages as well
    if unchanged:
        print_changes(added, removed, changed, remained)
    else:
        print_changes(added, removed, changed, {})
    # NOTE: update the requirements in the settings.ini file
    cprint("bold cyan", "Updating the requirements...")
    config['DEFAULT']['requirements'] = requirements_to_ini(new_requirements)
    cprint("bold cyan", "Saving the updated settings.ini file...")
    with open('settings.ini', 'w') as f:
        config.write(f)
    cprint("bold green", "Successfully updated the requirements in settings.ini!")
if __name__ == "__main__":
    app()