13.2. Working with Text files#

  • Text files:

    • Plain text

    • XML

    • JSON

    • Source code

  • When you open a file,3 modes are there:

    • Read mode,’r’

      • If file allready exists,python will read it

      • If file doesn’t exists,python will give error

        • so wrap it in try block

    • Write mode,’w’

      • If file allready exists,python will overwrite it

      • If file doesn’t exists,python will create it

    • Append mode,’a’

      • If file allready exists,python will append text in end

      • If file doesn’t exists,python will create it

13.2.1. Read the file#

try:
    with open('sahil.txt','r') as f:
        text=f.read()
    
except FileNotFoundError:
    text=none

print(text)

A
B
C
D
E
F

13.2.2. Write to file#

l=['A','B','C']
with open('sahil.txt','w') as f:
        for i in l:
            f.write(i)

13.2.2.1. Check the file#

with open('sahil.txt') as f:
        text=f.read()

print(text) ### previous text got overwritten
# also,no line separators by default

ABC

13.2.2.2. Adding the new line manually#

l=['A','B','C']
with open('sahil.txt','w') as f:
        for i in l:
            f.write(i)
            f.write('\n')

13.2.2.3. Check the file#

with open('sahil.txt') as f:
        text=f.read()

print(text)

A
B
C

13.2.3. Append to File#

l=['D','E','F']
with open('sahil.txt','a') as f:
        for i in l:
            f.write(i)
            f.write('\n')

13.2.4. Check the file#

with open('sahil.txt','r') as f:
        text=f.read()

print(text)

A
B
C
D
E
F