Files part2

Python

 #create one file name with meera1.txt

a=open('meera1.txt','w')

print("enter any text until you press '~' symbol")

#enter any text

#I want to enter text into the file until I press '~'

 while True:

    s=input()#it takes string into LHS variable s

    if s!='~':

        a.write(s+"\n")

    else:

        break

a.close()

"""

meera1.txt

rueiorueiorueioureo

rueiorueoiru

 

"""

#read the existing  file name 'meera1.txt'

a=open('meera1.txt','r')

#read the file

s=a.read()

print(s)

a.close()

"""

meera1.txt

rueiorueiorueioureo

rueiorueoiru

 """

#append the text to the existing  file name 'meera1.txt'

a=open('meera1.txt','a')

a.write("I'm santhoshkumar")

##a.append()

a.close()

"""

meera1.txt

rueiorueiorueioureo

rueiorueoiru

I'm santhoshkumar

"""

import fileinput as fi

#append the text to begining of the file to the existing  file name 'meera1.txt'

a='F:\Programs\ESC\meera2.txt'

##a=open('meera2.txt','r+')

for i in fi.FileInput(a,inplace=1):

    if 'visakhapatnam' in i:

        i=i.rstrip()

        i=i.replace(i,i+'Guntur is containment zone'+'\n')

    print(i)

 

##a.close()

"""

meera2.txt

Dear Team,

visakhapatnam

guntur

I'm santhoshkumarGood morning all

After executing the above code:

meera2.txt

 import os,sys

#count the number of line, words and characters from the existing file

fname=input("enter filename: ")

if os.path.isfile(fname): #this condition checks whether the file exits or not

    f=open(fname,'r')

else:

    print(fname+' does not exist')

    sys.exit()

#no of lines,words and characters

l=w=c=0

#read line by line

for i in f:

    words=i.split()

    l+=1 #it counts no of lines in the file

    w=w+len(words)

    c=c+len(i)#it counts no of characters in the file

print("no of lines=",l)

print("no of words=",w)

print("no of chars=",c)

f.close()

"""

enter filenamemeera2.txt

no of lines= 20

no of words= 16

no of chars= 144

Case2:

enter filename: meera3.txt

meera3.txt does not exist

"""

Dear Team,

 visakhapatnamGuntur is containment zone

 guntur

 Guntur is containment zone

 I'm santhoshkumarGood morning all

 """

 Binary files:

#using binary files

#open the image file in binary mode

f=open('image.png','rb') #exiting image opened, f points to it

a=open('pytlogo.png','wb')#new png file is created, a points to it

#read the binary file and copy into a

bytes=f.read()

a.write(bytes) #copying into pytlogo.png

 #close the files

a.close()

f.close()   

Binary files handles the data in the form of bytes. It is used to read,write the text,audio, video files.

To open a existing binary files , use ‘rb’ mode. Representing binary file.

To read the binary file  use read() method.

If you want to write the binary file use ‘wb’ mode

Related Video: https://youtu.be/EwP28YFF00s

Next: Files with Exception handling

https://youtu.be/idJOrgHYIfQ

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