Parse Text with Python - python-3.x

Question

I have data like the example data below in a text file. What I would like to do is search through the text file and return everything between "SpecialStuff" and the next ";", like I've done with the example out put. I'm pretty new to python so any tips are greatly appreciated, would something like .split() work?
Example Data:
stuff:
1
1
1
23
];
otherstuff:
do something
23
4
1
];
SpecialStuff
select
numbers
,othernumbers
words
;
MoreOtherStuff
randomstuff
##123
Example Out Put:
select
numbers
,othernumbers
words

Answer 1

You can try this:
file = open("filename.txt", "r") # This opens the original file
output = open("result.txt", "w") # This opens a new file to write to
seenSpecialStuff = 0 # This will keep track of whether or not the 'SpecialStuff' line has been seen.
for line in file:
if ";" in line:
seenSpecialStuff = 0 # Set tracker to 0 if it sees a semicolon.
if seenSpecialStuff == 1:
output.write(line) # Print if tracker is active
if "SpecialStuff" in line:
seenSpecialStuff = 1 # Set tracker to 1 when SpecialStuff is seen
This returns a file named result.txt that contains:
select
numbers
,othernumbers
words
This code can be improved! Since this is likely a homework assignment, you'll probably want to do more research about how to make this more efficient. Hopefully it can be a useful starting ground for you!
Cheers!
EDIT
If you wanted the code to specifically read the line "SpecialStuff" (instead of lines containing "SpecialStuff"), you could easily change the "if" statements to make them more specific:
file = open("my.txt", "r")
output = open("result.txt", "w")
seenSpecialStuff = 0
for line in file:
if line.replace("\n", "") == ";":
seenSpecialStuff = 0
if seenSpecialStuff == 1:
output.write(line)
if line.replace("\n", "") == "SpecialStuff":
seenSpecialStuff = 1

Answer 2

with open('path/to/input') as infile, open('path/to/output', 'w') as outfile: # open the input and output files
wanted = False # do we want the current line in the output?
for line in infile:
if line.strip() == "SpecialStuff": # marks the begining of a wanted block
wanted = True
continue
if line.strip() == ";" and wanted: # marks the end of a wanted block
wanted = False
continue
if wanted: outfile.write(line)

Answer 3

Don't use str.split() for that - str.find() is more than enough:
parsed = None
with open("example.dat", "r") as f:
data = f.read() # load the file into memory for convinience
start_index = data.find("SpecialStuff") # find the beginning of your block
if start_index != -1:
end_index = data.find(";", start_index) # find the end of the block
if end_index != -1:
parsed = data[start_index + 12:end_index] # grab everything in between
if parsed is None:
print("`SpecialStuff` Block not found")
else:
print(parsed)
Keep in mind that this will capture everything between those two, including new lines and other whitespace - you can additionally do parsed.strip() to remove leading and trailing whitespaces if you don't want them.