如何在文件python中提取文本

Question

How to extract a text in a file with python. - A text begin with chaine.

My code is

fichier= open("Service.txt", "r")
for ligne in fichier:
  if ligne==chaine:
  #What do I do ? 
fichier.close()

Answer 1

You have to check in operator with string.

Like

>>> a = "cheine is good"
>>> "cheine" in a
True

So your code must be like.

fichier= open("Service.txt", "r")
for ligne in fichier:
  if chaine in ligne:
  #What do I do ? 
fichier.close()

If you have to check start only in line, then you can check ligne.startswith .

Answer 2

with open("Service.txt", "r") as f:
    lines = f.readlines()
chaines = [line for line in lines if line.startswith("chaine")]
for chaine in chaines:
    print("Some chaine, whatever that is", chaine)

This uses a list comprehension, the if part will filter out any line that doesn't start with "chaine" .

The with block is a context manager, it makes sure to close the file when the block ends, even if there is an exception.

Answer 3

If I understood question correctly:

test.txt

fsdfj ljkjl
sdfsdf ljkkk
some ldfff
fffl lll
ppppp

script:

chaine = 'some'

with open("test.txt", "r") as f:
    text = f.read()
    i = text.find(chaine)
    print(text[i:])

output:

some ldfff
fffl lll
ppppp

Answer 4

You can try like this,

>>> with open('Service.txt', 'r') as f:
...     val = f.read()
>>> if "cheine" in val:
... # do something

Answer 5

with open("Service.txt", "r") as fichier:
    for ligne in fichier.readlines():
      if 'Call' in ligne:
      #What do I do 

Try this.

Answer 6

Thank you all.

This is a file (Service.txt) while, I use to recover a text with it.

A text is only:

     Supplementary service  =  Call forwarding unconditional


                            =  Call waiting


                            =  Calling line identification presentation

Service.txt

Thank you.