Helped me to identify 1000 markdown codeblocks in my hugo blog. Syntax Highlighter was quite happy after appliying this!

identify-codeblocks.py

#!/usr/bin/env python3

import sys
import re
import signal

f = sys.argv[1]


def signal_handler(sig, frame):
    sys.exit(0)
    
signal.signal(signal.SIGINT, signal_handler)

def print_codeblock(data):
    for codeline in data:
        print(codeline, end = '')
        if re.findall('^```\s?', codeline):
            break

def what_code():
    print("What language is this:")
    print("p - python")
    print("f - fish")
    print("b - bash")
    print("g - go")
    print("m - markdown")
    print("r - ruby")
    print("h - html")
    print("pu - puppet")
    print("y - yaml")
    print("c - custom")

    try:
        r = input("Choice: ")
    except KeyboardInterrupt:
        sys.exit(1)

    if r == "p":
        res = " python"
    elif r == "f":
        res = " fish"
    elif r == "b":
        res = " bash"
    elif r == "g":
        res = " go"
    elif r == "r":
        res = " ruby"
    elif r == "pu":
        res = " puppet"
    elif r == "h":
        res = " html"
    elif r == "m":
        res = " markdown"
    elif r == "y":
        res = " yaml"
    elif r == "c":
        res = " " + input("Enter Custom: ")
    else:
        res = ""

    return "```" + str(res) + "\n"

# with is like your try .. finally block in this case
with open(f, 'r') as file:
    # read a list of lines into data
    data = file.readlines()

# loop over file lines
no=0
for pos, line in enumerate(data):

    if re.findall('^```', line):

        # count ``` occurences
        no = no + 1

        # ignore closing ``` if its the second
        if no % 2 == 0:
            continue

        # ignore already typed codeblocks
        if re.findall('^```\s?\S', line):
            continue

        print("\nFound Codeblock:")
        print('\033[92m')
        print(line, end = '')
        print_codeblock(data[pos+1:])
        print('\033[0m')
        res = what_code()
        data[pos] = res


# and write everything back
with open(f, 'w') as file:
    file.writelines(data)

output.txt

Found Codeblock:

```
for f in *-Ride.gpx
  set -l points (math (grep -c "trkpt" $f) / 30)
  gpsbabel -rt -i gpx -f $f -x simplify,count={$points} -o gpx -F SIMPLIFIED-$f
end
```

What language is this:
p - python
f - fish
b - bash
g - go
m - markdown
r - ruby
h - html
pu - puppet
y - yaml
c - custom
Choice: f