hello beautiful people so i have a text file like this :
user = user447
pass = 455555az
type = registred
date = 1 year
and i want to read the file and rewrite it like this
- user|pass|type|date, line by line, i tried so many ways , i seem stuck since i have to deal with 1 million account
with open(file, "r") as f: data = [] for line in f: key = line.rstrip('n').split('=') key1 = key[1:2]
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Answer
You don’t need to read the entire file all at once, instead, you can just read it in parts and write as you read (note the with
block is used for two open()
context managers, though you can nest them inside each other just as easily)
with open(source) as fh_src, open(destination, "w") as fh_dest: block = [] for lineno, line in enumerate(fh_src, 1): # .split("=", 1)[-1] captures everything after the first = # this is also an opportunity to verify the key block.append(line.split("=", 1)[-1].strip()) if len(block) == 4: fh_dest.write("{}|{}|{}|{}n".format(*block)) block = [] # reset block after each write
it’s definitely worth creating some safeguards, however!
- checking if lines really start with some key if you have a set of known keys or have some you intend to omit, or if you have some dynamic set of keys (say some users have a collection of previous password hashes, or different comments)
- checking
if block
at the end (it should be cleared and write!) - checking
=
is really in each line or that any comments are kept or discarded - opening
"w"
will removedestination
if it exists already (perhaps from a botched previous run), which may be undesirable
(lineno
is only included to simplify discovering bad lines)