reading and writing data in a text file with python
#for reading and writing data in a text file with python
#First you must have a file Open or create a new file have it loaded in memory.
# Open function to open the file "MyFile1.txt"
# (same directory) in append mode and
file1 = open("MyFile.txt","a")
# store its reference in the variable file1
# and "MyFile2.txt" in D:Text in file2
file2 = open(r"D:TextMyFile2.txt","w+")
# Opening and Closing a file "MyFile.txt"
# for object name file1.
file1 = open("MyFile.txt","a")
file1.close()
# Program to show various ways to read and
# write data in a file.
file1 = open("myfile.txt","w")
L = ["This is Delhi n","This is Paris n","This is London n"]
# n is placed to indicate EOL (End of Line)
file1.write("Hello n")
file1.writelines(L)
file1.close() #to change file access modes
file1 = open("myfile.txt","r+")
print "Output of Read function is "
print file1.read()
print
# seek(n) takes the file handle to the nth
# bite from the beginning.
file1.seek(0)
print "Output of Readline function is "
print file1.readline()
print
file1.seek(0)
# To show difference between read and readline
print "Output of Read(9) function is "
print file1.read(9)
print
file1.seek(0)
print "Output of Readline(9) function is "
print file1.readline(9)
file1.seek(0)
# readlines function
print "Output of Readlines function is "
print file1.readlines()
print
file1.close()
# Python program to illustrate
# Append vs write mode
file1 = open("myfile.txt","w")
L = ["This is Delhi n","This is Paris n","This is London n"]
file1.close()
# Append-adds at last
file1 = open("myfile.txt","a")#append mode
file1.write("Today n")
file1.close()
file1 = open("myfile.txt","r")
print "Output of Readlines after appending"
print file1.readlines()
print
file1.close()
# Write-Overwrites
file1 = open("myfile.txt","w")#write mode
file1.write("Tomorrow n")
file1.close()
file1 = open("myfile.txt","r")
print "Output of Readlines after writing"
print file1.readlines()
print
file1.close()
Output of Readlines after appending
['This is Delhi n', 'This is Paris n', 'This is London n', 'Today n']
Output of Readlines after writing
['Tomorrow n']
