Python open file for read and write code example

Example 1: python write to file

file = open(“testfile.txt”,”w”) 
 
file.write(“Hello World”) 
file.write(“This is our new text file”) 
file.write(“and this is another line.”) 
file.write(“Why? Because we can.”) 
 
file.close()

Example 2: python file handling

with open('filename', 'a') as f: # able to append data to file
	f.write(var1) # Were var1 is some variable you have set previously
	f.write('data') 
	f.close() # You can add this but it is not mandatory 

with open('filename', 'r') as f: # able to read data from file ( also is the default mode when opening a file in python)

with open('filename', 'x') as f: # Creates new file, if it already exists it will cause it to fail

with open('filename', 't') as f: # opens the file in text mode (also is defualt)

with open('filename', 'b') as f: # Use if your file will contain binary data
  
with open('filename', 'w') as f: # Open file with ability to write, will also create the file if it does not exist (if it exists will cause it to fail)
  
with open('filename', '+') as f: # Opens file with reading and writing

# You can combine these as you like with the + for reading and writing

Example 3: python open and read file with

with open('pagehead.section.htm','r') as f:
    output = f.read()

Example 4: how to write a python variable to a file

#use pickle

import pickle
dict = {'one': 1, 'two': 2}
file = open('dump.txt', 'w')
pickle.dump(dict, file)
file.close()

#and to read it again
file = open('dump.txt', 'r')
dict = pickle.load(file)

Example 5: read and write to file python

file = open(“testfile.txt”, “r+”)

Example 6: read and write file in python

#Write a Python program to create a file of numbers by taking input from the user and then display the content of the file. You can take input of non-zero numbers, with an appropriate prompt, from the user until the user enters a zero to create the file assuming that the numbers are non-zero.  
    f = open ('NumFile.txt','w')
    while True :
        no = int(input("enter a number (0 for exit)"))
        if no == 0 :
            print("you entered zero(0) ....... \n now you are exit  !!!!!!!!!!!")
            break
        else :
            f.write(str(no)+"\n")
    f.close() 
    f1 = open ('NumFile.txt','r')
    print("\ncontent of file :: \n",f1.read())
    f1.close()