Given a binary file that contains some sentences (space separated words), let’s write a Python program to modify or alter any particular word of the sentence.
Approach:
Step 1: Searching for the word in the binary file.
Step 2: While searching in the file, the variable “pos” stores the position of file pointer record then traverse(continue) reading of the record.
Step 3: If the word to be searched exists then place the write pointer (to ending of the previous record) i.e. at pos.
Step 4: Call write() function to take the new record.
Step 5: Write the new object at the position “pos” and hence the record is updated and print “record successfully updated”.
Step 6: If the word does not exists then print “record not found”.
Implementation
Let’s suppose the content of the binary file is:
Python3
# Python program to modify the# content of binary file# Function to update the# content of binary filedef update_binary(word, new) # string variable to store # each word after reading # from the file string = b"" # Flag variable to check # if the record is found or # not Flag = 0 # Open the file in r + b mode which means # opening a binary file for reading and # writing with open('file.txt', 'r + b') as file: pos = 0 # Reading the content of the # file character by character data = string = file.read(1) # Looping till the end of # file is reached while data: data = file.read(1) # Checking if the space is reached if data == b" ": # checking the word read with # the word entered by user if string == word: # Moving the file pointer # at the end of the previously # read record file.seek(pos) # Updating the content of the file file.write(new) Flag = 1 break else: # storing the position of # current file pointer i.e. at # the end of previously read record pos = file.tell() data = string = file.read(1) else: # Storing the data of the file # in the string variable string += data continue if Flag: print("Record successfully updated") else: print("Record not found") # Driver code# Input the word to be found# and the new wordword = input("Enter the word to be replaced: ").encode()new = input("\nEnter the new word: ").encode()update_binary(word, new) |
Output:
Text file:
