Python PIP Install throws TypeError: unsupported operand type(s) for -=: 'Retry' and 'int'

参考 https://stackoverflow.com/questions/37495375/python-pip-install-throws-typeerror-unsupported-operand-types-for-retry/46970344#46970344

apt-get remove python-pip python3-pip
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
python3 get-pip.py

如果运行get-pip.py很慢，修改文件中的args = ["install", "--upgrade", "--force-reinstall", "-i", "https://pypi.douban.com/simple"] + args，新增了pip源即可。

bazel 2.0.0新版本问题

更新了最新的bazel，报错：
name 'maven_server' is not defined
name 'maven_jar' is not defined

新版本不支持这些了，需要切换到旧版本的bazel，参考：https://github.com/google/mediapipe/issues/337

mac系统如何降级bazel，参考https://github.com/bazelbuild/homebrew-tap/issues/39

统计文件夹中所有wav的时长

ls | xargs -i sox {} -n stat 2>&1 | grep Length | awk '{print $3}' | awk '{sum+=$1} END {print sum}'

vim中取消鼠标点击时的visual模式

在~/.vimrc中添加:set mouse-=a

参考http://smzz.org/node/25

大量http连接TIME_WAIT

netstat -alntp | grep 38080，发现大量的TIME_WAIT，不确定是否正常。

参考了https://cloud.tencent.com/developer/article/1038071，修改/etc/sysctl.conf，增加三行：
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1

/sbin/sysctl -p 使配置生效。

不确定是否能解决问题，待观察。

pip install openpyxl问题解决

使用python2安装openpyxl时一直遇到一个问题：
Collecting openpyxl
  Using cached https://files.pythonhosted.org/packages/f4/5f/fb8706fba43b46716e252fdd3ffdfe801a63a0f4663b80b6f3421d85ab70/openpyxl-3.0.2.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-qUECOe/openpyxl/setup.py", line 28, in <module>
        from importlib.util import module_from_spec, spec_from_file_location
    ImportError: No module named util

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-qUECOe/openpyxl/

发现装3.x版本都不行，pip install pip install openpyxl==2.6.4，换成旧版本之后，解决问题。

修改brew update镜像源

替换brew.git：
cd "$(brew --repo)"
git remote set-url origin https://mirrors.ustc.edu.cn/brew.git

替换homebrew-core.git：
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://mirrors.ustc.edu.cn/homebrew-core.git