Merge a tex file with all of it's \inputs recursively.

mergetex.py

#!/usr/bin/env python3

import sys

def merge(input_tex):
    new_lines = []

    for c_line in input_tex:
        # check for line comment
        line = c_line
        more = ''
        for i in range(0, len(c_line)):
            if c_line[i] == '%' and c_line[i-1] != '\\':
                line = c_line[:i]
                more = c_line[i:].replace('\n','')
                break

        line = line.replace('\n','')

        if "\\input{" in line:
            begIdx = line.index("\\input{")
            endIdx = line.index("}", begIdx)
            source = line[begIdx+7:endIdx] + '.tex'

            # append text before \input{source}
            new_lines.append(line[:begIdx])

            # append lines from input source
            input_lines = []
            with open(source, 'r') as f:
                input_lines = f.readlines()
            # recursively process inputs.
            [new_lines.append(l) for l in merge(input_lines)]

            # append lines after \input{source}
            new_lines.append(line[endIdx+1:])
        else:
            new_lines.append(line)

        # reattach comment portion of line
        if len(more) > 0:
            new_lines[-1] = new_lines[-1] + more

    return new_lines

if __name__ == '__main__':
    for input_file in sys.argv:
        if not input_file.endswith('.tex'):
            continue

        with open(input_file, 'r') as f:
            lines = f.readlines()

        [print(line) for line in merge(lines)]