<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def open_file(self, file_):
 """ Receives a file path has input and returns a string with the contents of the file """

        with open(file_, 'r', encoding='utf-8') as file:
            text = ''
            for line in file:
                text += line
        return text