how to read and write text files in python

1#the way i learned it
2#plus explanations
3
4from sys import * #this is for making it more flexible
5
6#so now we gotta open a file to write in
7
8f = open("haha.txt", "w") # the w means WRITING
9#now we gotta write something
10
11f.write(str(argv[1])) # the str means change it into a string of letters
12#argv[1] means it's the thing you type after the python run thing
13#for example: "python run.py helo"
14
15#now we gotta finish it
16f.close()
17
18#if you want to see whats in it...
19
20f = open("haha.txt", "r") #r means READING
21print(f.read()) # this prints what you wrote
22
23#example input and output
24
25#            python run.py helo
26#   helo

1#for reading and writing data in a text file with python
2#First you must have a file Open or create a new file have it loaded in memory.
3# Open function to open the file "MyFile1.txt" 
4# (same directory) in append mode and 
5file1 = open("MyFile.txt","a") 
6
7# store its reference in the variable file1 
8# and "MyFile2.txt" in D:\Text in file2 
9file2 = open(r"D:\Text\MyFile2.txt","w+") 
10
11# Opening and Closing a file "MyFile.txt" 
12# for object name file1. 
13file1 = open("MyFile.txt","a") 
14file1.close() 
15
16# Program to show various ways to read and 
17# write data in a file. 
18file1 = open("myfile.txt","w") 
19L = ["This is Delhi \n","This is Paris \n","This is London \n"] 
20
21# \n is placed to indicate EOL (End of Line) 
22file1.write("Hello \n") 
23file1.writelines(L) 
24file1.close() #to change file access modes 
25
26file1 = open("myfile.txt","r+") 
27
28print "Output of Read function is "
29print file1.read() 
30print
31
32# seek(n) takes the file handle to the nth 
33# bite from the beginning. 
34file1.seek(0) 
35
36print "Output of Readline function is "
37print file1.readline() 
38print
39
40file1.seek(0) 
41
42# To show difference between read and readline 
43print "Output of Read(9) function is "
44print file1.read(9) 
45print
46
47file1.seek(0) 
48
49print "Output of Readline(9) function is "
50print file1.readline(9) 
51
52file1.seek(0) 
53# readlines function 
54print "Output of Readlines function is "
55print file1.readlines() 
56print
57file1.close() 
58
59# Python program to illustrate 
60# Append vs write mode 
61file1 = open("myfile.txt","w") 
62L = ["This is Delhi \n","This is Paris \n","This is London \n"] 
63file1.close() 
64
65# Append-adds at last 
66file1 = open("myfile.txt","a")#append mode 
67file1.write("Today \n") 
68file1.close() 
69
70file1 = open("myfile.txt","r") 
71print "Output of Readlines after appending"
72print file1.readlines() 
73print
74file1.close() 
75
76# Write-Overwrites 
77file1 = open("myfile.txt","w")#write mode 
78file1.write("Tomorrow \n") 
79file1.close() 
80
81file1 = open("myfile.txt","r") 
82print "Output of Readlines after writing"
83print file1.readlines() 
84print
85file1.close() 
86
87Output of Readlines after appending
88['This is Delhi \n', 'This is Paris \n', 'This is London \n', 'Today \n']
89
90Output of Readlines after writing
91['Tomorrow \n']

1#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.  
2    f = open ('NumFile.txt','w')
3    while True :
4        no = int(input("enter a number (0 for exit)"))
5        if no == 0 :
6            print("you entered zero(0) ....... \n now you are exit  !!!!!!!!!!!")
7            break
8        else :
9            f.write(str(no)+"\n")
10    f.close() 
11    f1 = open ('NumFile.txt','r')
12    print("\ncontent of file :: \n",f1.read())
13    f1.close()
14
15