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版本：0.17.0+

python howto

module:log​

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module:hashlib​

md5​

implementation

import hashlib

def get_md5(s):

    md5 = hashlib.md5()
    md5.update(s.encode('utf-8'))
    return md5.hexdigest()

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module:re​

multi-line match​

In fact, the real multi-line match means:

  1. allow match cross lines
  2. allow \n to be .

So, there is two flags to set: re.MULTIPLE and re.DOTALL like this: picture 82

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module:typing​

TypedDict NotRequired VS Optional​

picture 1

Avoid using NotRequired and Optional picture 2

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TypedDict self-reference​

Here is what I want:

from typing import List, TypedDict

class TocItem(TypedDict):
    level: int
    title: str
    children: List[TocItem]

However, it doesn't work since one property can not fetch the outer class.

There are at least two remedies, and I recommend to add one line in the top:

from __future__ import annotations

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module:virtualenv​

how to install and use virtualenv in python​

# should use a local pip
pip install virtualenv

virtualenv YOUR/DIR

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conda​

change default startup behavior in zsh​

# .zshrc
# >>> conda initialize >>>
# !! Contents within this block are managed by 'conda init' !!
__conda_setup="$('/usr/local/anaconda3/bin/conda' 'shell.zsh' 'hook' 2> /dev/null)"
#if [ $? -eq 0 ]; then
#    eval "$__conda_setup"
#else
    if [ -f "/usr/local/anaconda3/etc/profile.d/conda.sh" ]; then
        . "/usr/local/anaconda3/etc/profile.d/conda.sh"
    else
        export PATH="/usr/local/anaconda3/bin:$PATH"
    fi
#fi
unset __conda_setup
# # <<< conda initialize <<<

how to print colorful text in terminal, mac and windows​

use termcolor

pip install colorama
from colorama import init

# call this when init, so that all the ascii color would be displayed in windows
init()

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how to install specific python in mac​

  1. install homebrew
  2. brew install pyenv
  3. pyenv install VERSION
  4. pyenv global VERSION

how to print colored text to console/terminal in python​

from termcolor import colored

# `colored` return a `Text` object, which can be called by `print()`
text = colored('Hello, World!', 'red', attrs=['reverse', 'blink', "bold"])
print(text)

⚠️ 不过注意，这些彩色实现，其实都是基于 ascii 码的，也就是 .\[\d+m这样的一个正则字符，并且不可以被 markdown 解析渲染。因此如果不单单是往控制台输出，还想保存成文件的话，则需要做相应处理。

  1. 最简单与直观的做法就是直接替换掉这些 ascii 标识，可以用sed很方便实现这一点，例如 python xxx | sed -r "s|.\[\d+m||g"。
  2. 如果有多个输出目标，则可以考虑写两套文本生成算法，这个也比较推荐，尤其是生成 html 格式的彩色文本还是极其方便的，例如：<p style="color: XXX">YYY</p>
  3. 还有一种，专属于 markdown 的 ascii 码渲染方案，基于 github 的ascii2html仓库，不过看 issue，貌似功能不够稳健，然后是基于 c 的，我不怎么会运行……

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