I keep getting this error and i don't understand why.

Traceback (most recent call last):
  File "E:\University\Workspace eclipse\dictionares\src\dcts\dicts.py", line 105, in <module>
    fr_runt()
  File "E:\University\Workspace eclipse\dictionares\src\dcts\dicts.py", line 95, in fr_runt
    run.run()
  File "E:\University\Workspace eclipse\dictionares\src\dcts\dicts.py", line 58, in run
    self.data.write(file, key, value)
  File "E:\University\Workspace eclipse\dictionares\src\dcts\dicts.py", line 23, in write
    fh = open(file, 'a')
TypeError: coercing to Unicode: need string or buffer, type found

I'm trying to make a so called 'database', working with dictionaires, and it won't let me write down the changes in the file.
I'll put the code bellow:

'''
Created on Feb 20, 2012

@author: sin
'''
import os
import sys
import time
import random
class data:
    def __init__(self, file):
        self.file = file
        self.dic = {}

    def print_dic(self, file):
        fh = open(file, 'r')
        line = open(file).read().splitlines()
        for i in range(0, len(line)):
            print i, "-"*2, line[i], '\n'
        fh.close()
            
    def write(self, file, key, value):
        fh = open(file, 'a')
        self.dic[key] = value
        fh.write(str(self.dic))
        fh.close()

    def delet(self, file, single):
        fh = open(file, 'r')
        data_lines = fh.readlines()
        fh.close()
        del data_lines[:single]
        fh = open(file, 'w')
        for i in range(0, len(data_lines)):
            fh.write(str(data_lines[i]))
        fh.close()
        
    def clear(self, file):
        fh = open(file, 'w')
        fh.write('')
        fh.close()
        

class main:
    def __init__(self, data):
        self.data = data
        
    def run(self):
        while True:
            print """
        1. Add to database
        2. Remove from database
        3. Print database
"""
            cmd = raw_input("\\\\:")
            if cmd == '1' or cmd == '1.':
                key = raw_input("Key: ")
                value = raw_input("Value: ")
                self.data.write(file, key, value)
                print "Your key: " + str(key) + " was added to our database, with it's value of", value + '.\n', '-' * 60
            elif cmd == '2' or cmd == '2.':
                self.data.print_dic(file)
                single = int(raw_input("Position: "))
                self.data.delet(file, single)
                print '-' * 60
            elif cmd == '3' or cmd == '3.':
                self.data.print_dic(file)
            elif cmd == 'clear':
                self.data.clear(file)
                print "You have succesfully deleted all data from the database.\n", '-' * 60
            elif cmd == 'exit':
                exit()
            else: print "Invalid command.\n", '-' * 60
            

def fr_runt():
            print """Do you wish to load an existing database, or to create a new one?
            1. Load
            2. Create
            """
            while True:
                cmd = raw_input("\\\\: ")
                if cmd == '1' or cmd == '1.':
                    pathname = os.path.dirname(sys.argv[0])
                    print "Your current path: \n", pathname
                    print 'sys.argv[0]=' + str(sys.argv[0])
                    file = raw_input("Insert database name: ") + '.txt'
                    dt = data(file)
                    run = main(dt)
                    if os.path.isfile(str(pathname) + '\\' + file):
                        print "Your database was loaded."
                        time.sleep(2)
                        x = random.randint(0, 10)
                        print "Please, wait", x, 'seconds.'
                        time.sleep(x)
                        run.run()
                    else: print "Invalid file."
                elif cmd == '2' or cmd == '2.':
                    file = raw_input("Insert filename: ") + '.txt'
                    dt = data(file)
                    run = main(dt)
                    run.run()
                elif cmd == 'exit':
                    sys.exit()
                else: print "Invalid command."
fr_runt()

Dont use file as variable/argument is a built-in functions.

>>> f = open(file, 'a')
Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
TypeError: coercing to Unicode: need string or buffer, type found
>>> file
<type 'file'>
>>>
Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.