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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove(self):
 """Remove duplicate lines from text files"""

        num, sp, newfile = 0, "", []
        if os.path.isfile(self.filename):
            with open(self.filename, "r") as r:
                oldfile = r.read().splitlines()
                for line in oldfile:
                    if self.number:
                        num += 1
                        sp = ": "
                    if self.case_ins:
                        line = line.lower()
                    if self.ignore_blank and not line:
                        newfile.append(line)
                    elif line not in newfile:
                        newfile.append(line)
                    else:
                        if (self.args[0] in self.options[4:5] or
                                self.args[0] in self.options[6:7]):
                            if num == 0:
                                num = str()
                            print("{0}{1}{2}".format(num, sp, line))
            if self.args[0] not in self.options[6:7]:
                with open(self.filename, "w") as w:
                    for line in newfile:
                        w.write(line + "\n")
        else:
            self.not_access()