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Posted 2021-05-06

一開始下載的conda package可能是比較舊的版本, 記得更新
Conda 像是pip 一樣可以管理lib, 不過不限於python lib, 也能裝非python lib, 另外numpy, scikit等lib
是使用pre-compiled 的 MKL 版本, 更快. 而且也可以管理虛擬環境, 就像是pyenv

[Package download](https://conda.io/docs/user-guide/install/macos.html)


## update conda
```commandline
$conda upgrade conda
$conda upgrade --all
```

## create python2/3 env for general purpose
```commandline
$conda create -n py2 python=2
$conda create -n py3 python=3
```

## list all env
```commandline
$conda info --envs
```

or 
```
$ conda env list
```

## Activate env
```commandline
$ME0342:AIND leemeng$ source activate py3
(py3) ME0342:AIND leemeng$ 
```

## requirement / dependency sharing
= `pip freeze > requirements.txt`

```commandline
$conda env export > environment.yaml
```

## Install dependencies from file
```commandline
$conda install --file requirements.txt
```


## Create new env from existing .yaml
```commandline
$ conda env create -n test -f environment.yaml 
```

## Show dependencies of a env without activation
```commandline
$conda list -n test
```

## Delete a env
```commandline
$ conda env remove -n test
```

## List all non-Python package 
```commandline
$conda search --canonical  | grep -v 'py\d\d'
```

## Jupyter notebook
在jupyter notebook 裡頭要切換不同環境,記得想要使用的環境本身要安裝jupyter notebook
```commandline
conda install jupyter
```