python - 用于从文件中选择单个 Python 函数的 Bash 脚本

Question

对于 git alias problem ，我希望能够按名称从文件中选择一个 Python 函数。例如:

  ...
  def notyet():
      wait for it

  def ok_start(x):
      stuff
      stuff
      def dontgettrickednow():
         keep going
  #stuff
      more stuff

  def ok_stop_now():

在算法方面，以下内容足够接近:

1. 当找到匹配 /^(\s*)def $1[^a-zA-Z0-9]/ 的行时开始过滤>
2. 继续匹配，直到找到不是 ^\s*# 或 ^/\1\s] 的行(即, 一个可能缩进的评论，或者比前一个缩进更长的缩进)

(我真的不在乎是否拾取了以下函数之前的装饰器。结果是供人类阅读的。)

我试图用 Awk(我几乎不知道)来做到这一点，但它比我想象的要难一些。对于初学者，我需要一种方法来存储原始 def 之前的缩进长度。

Answer 1

使用 awk 的一种方式。代码有很好的注释，所以我希望它很容易理解。

infile 的内容:

  ...
  def notyet():
      wait for it

  def ok_start(x):
      stuff
      stuff
      def dontgettrickednow():
         keep going
  #stuff
      more stuff

  def ok_stop_now():

script.awk 的内容:

BEGIN {
        ## 'f' variable is the function to search, set a regexp with it.
        f_regex = "^" f "[^a-zA-Z0-9]"

        ## When set, print line. Otherwise omit line.
        ## It is set when found the function searched.
        ## It is unset when found any character different from '#' with less
        ## spaces before it.
        in_func = 0
}

## Found function.
$1 == "def" && $2 ~ f_regex {

        ## Get position of first 'd' in the line.
        i = index( $0, "d" )

        ## Sanity check. Never should success because the condition was
        ## checked before.
        if ( i == 0 ) {
                next
        }

        ## Get characters until matched index before, check that all of
        ## them are spaces, and get its length.
        indent = substr( $0, 0, i - 1 )
        if ( indent ~ /^[[:space:]]*$/ ) {
                num_spaces = length( indent )
        }

        ## Set variable, print line and read next one.
        in_func = 1
        print
        next
}

## When we are inside the function, line doesn't begin with '#' and
## it's not a blank line (only spaces).
in_func == 1 && $1 ~ /^[^#]/ && $0 ~ /[^[:space:]]/ {

        ## Get how many characters there are until first non-space. The result
        ## is the position of first non-blank, so substract one to get the number
        ## of spaces.
        spaces = match( $0, /[^[:space:]]/ )
        spaces -= 1

        ## If current indent is less or equal that the indent of function definition, then
        ## end of function found, so end processing.
        if ( spaces <= num_spaces ) {
                in_func = 0
        }
}

## Self-explanatory.
in_func == 1 { 
        print
}

像这样运行它:

awk -f script.awk -v f="ok_start" infile

输出如下:

  def ok_start(x):
      stuff
      stuff
      def dontgettrickednow():
         keep going
  #stuff
      more stuff