<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def module_imports_on_top_of_file( logical_line, indent_level, checker_state, noqa):
 r"""Place imports at the top of the file. Always put imports at the top of the file, just after any module comments and docstrings, and before module globals and constants. Okay: import os Okay: # this is a comment\nimport os Okay: '''this is a module docstring'''\nimport os Okay: r'''this is a module docstring'''\nimport os Okay: try:\n\timport x\nexcept ImportError:\n\tpass\nelse:\n\tpass\nimport y Okay: try:\n\timport x\nexcept ImportError:\n\tpass\nfinally:\n\tpass\nimport y E402: a=1\nimport os E402: 'One string'\n"Two string"\nimport os E402: a=1\nfrom sys import x Okay: if x:\n import os """

    def is_string_literal(line):
        if line[0] in 'uUbB':
            line = line[1:]
        if line and line[0] in 'rR':
            line = line[1:]
        return line and (line[0] == '"' or line[0] == "'")

    allowed_try_keywords = ('try', 'except', 'else', 'finally')

    if indent_level:  # Allow imports in conditional statements or functions
        return
    if not logical_line:  # Allow empty lines or comments
        return
    if noqa:
        return
    line = logical_line
    if line.startswith('import ') or line.startswith('from '):
        if checker_state.get('seen_non_imports', False):
            yield 0, "E402 module level import not at top of file"
    elif re.match(DUNDER_REGEX, line):
        return
    elif any(line.startswith(kw) for kw in allowed_try_keywords):
        # Allow try, except, else, finally keywords intermixed with imports in
        # order to support conditional importing
        return
    elif is_string_literal(line):
        # The first literal is a docstring, allow it. Otherwise, report error.
        if checker_state.get('seen_docstring', False):
            checker_state['seen_non_imports'] = True
        else:
            checker_state['seen_docstring'] = True
    else:
        checker_state['seen_non_imports'] = True