import os
def exchange(pair_file,before_file,after_file):
    with open(pair_file, 'r', encoding='cp932') as f:
        pair_table = (f.read()).split(",")
    before_values,after_values=[],[]
    for i in range(0,len(pair_table),2):
        before_values+=[pair_table[i]]
        after_values+=[pair_table[i+1]]
    if len(set(before_values))==len(pair_table)/2:    
        with open(before_file, 'r', encoding='UTF-8') as f:
            before_file = f.read()    
        after_file_temp = before_file    
        for i in range(len(before_values)):
            after_file_temp = after_file_temp.replace(str(before_values[i]),after_values[i])        
        with open(after_file, 'w', encoding='UTF-8') as f:
           f.write(after_file_temp)

script_dir = os.path.dirname(os.path.abspath(__file__))
exchange(os.path.join(script_dir,'pair_data.txt'),os.path.join(script_dir,'before_file.txt'),os.path.join(script_dir,'after_file.txt'))