######_________________ Task ____________#####


file = open('/home/ec2-user/sample.txt','r')
for line in file:
  print(line)
file.close()

file = open('sample.txt','r')
for line in file:
  if 'linux' in line.lower():
    print(line)
file.close()

file = open('sample.txt','r')
for line in file:
  if 'linux' in line.lower():
    print(line.lower().replace('linux','<<linux>>'))
file.close()

## N.o of line

file = open('sample.txt','r')
nol = 0
for line in file:
  nol = nol + 1
print(nol)
file.close()

## N.o of  words

file = open('sample.txt','r')
now = 0
for item in file:
    now += len(item.split())
print(now)
file.close()

## Starts with linux

file = open('sample.txt','r')

for line in file:

  if line.lower().startswith('linux'):
    print(line)

file.close()

## line number

file = open('sample.txt','r')
ln = 1

for line in file:
  print(ln,line)
  ln += 1

file.close()

file = open('sample.txt','r')
ln = 1
for line in file:
  if line.lower().startswith('linux'):
    print(ln,line)
  ln += 1
file.close()

## Strip

s1 = ""
s2 = "  "
s3 = " dd "
s4 = "---------prince---------------"

print(s4.strip("-"))

print(s4.lstrip("-"))

print(s4.rstrip("-"))

print(s1.strip(),s2.strip())

print(s3.strip())

r1 = len(s1.strip())
r2 = len(s2.strip())
print(r1)
print(r2)

## Empty lines

file = open('sample.txt','r')
x = 1

for line in file:
  if len(line.split()) == 0:
    print(x,line)
  x += 1
file.close()

file = open('sample.txt','r')
x = 1

for line in file:
  if len(line.split()) != 0:
    print(x,line)
  x += 1
file.close()

file = open('sample.txt','r')
for line in file:
  if line.lstrip().rstrip().startswith("#"):
    print(line)
file.close()

file = open('sample.txt','r')
for line in file:
  if not line.lstrip().rstrip().startswith("#"):
    print(line)
file.close()

## Write

file = open('myfile.txt','w')
file.write("I'am first line")
file.write("I'm second line")
file.write("I'm third line")
file.close()

! cat myfile.txt

file = open('myfile.txt','w')
file.write("I'am first line\n")
file.write("I'm second line\n")
file.write("I'm third line\n")
file.close()

! cat myfile.txt

fileIn = open('sample.txt','r')
fileOut = open('result.txt','w')

for line in fileIn:
  if not line.lstrip().rstrip().startswith('#'):
    if len(line.strip()) != 0:
      fileOut.write(line)
fileOut.close()
fileIn.close()

! cat result.txt