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Can Python do this?

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Join Date: Nov 2009

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Reputation: P00dle is an unknown quantity at this point

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P00dle

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Can Python do this?

27 Days Ago

Hi,

I am reading data from a file. The data is mostly text, but has a small bit of binary in it, as well as a linefeed at the end of every block of text. Can Python read all of it and write it to another file, while not changing the binary or the linefeed?

I have tried looking around online, but couldn't find the answer. Daniweb is on of the best Forums out there, so I am asking it here.

Also, is there anyway in Python that you can test whether or not a line of data is binary?

Last edited by P00dle; 27 Days Ago at 5:32 am.

I wanted to ask God for a bike, but I know thats not how he does things, so I stole one and asked for forgiveness.

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Join Date: May 2009

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Reputation: sravan953 has a little shameless behaviour in the past

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sravan953

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Posting Whiz in Training

27 Days Ago

If you don't already know:

 Help with Code Tags 
 python Syntax (Toggle Plain Text) 
(identifier)=open("(file.txt)",'r'(or)'w')
(another_identifier)=(identifier).read()
#That's how you get text from a file which is now stored as a String in (another_identifier)
#Now, mess around!
(identifier)=open("(file.txt)",'r'(or)'w')
(another_identifier)=(identifier).read()
#That's how you get text from a file which is now stored as a String in (another_identifier)
#Now, mess around!

www.uberpix.wordpress.com
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Twitter: sravan953

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Join Date: Nov 2009

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Reputation: P00dle is an unknown quantity at this point

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P00dle

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Junior Poster in Training

27 Days Ago

No, I didnt already know, since I started Python 2 days ago, and have never done another language before that...

Thank you though.

I'm not going to check for binary anymore, instead I will test every line in the file against a regular expression. That is the end of the file. After that I will use pickle to dump it to a new file.

I wanted to ask God for a bike, but I know thats not how he does things, so I stole one and asked for forgiveness.

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Join Date: Nov 2009

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Reputation: P00dle is an unknown quantity at this point

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P00dle

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Junior Poster in Training

27 Days Ago

What I asked was if there is anyway to check whether or not input received from a file is in binary.

All your post says is how to read from a file.

I wanted to ask God for a bike, but I know thats not how he does things, so I stole one and asked for forgiveness.

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Join Date: Sep 2009

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Reputation: ov3rcl0ck is an unknown quantity at this point

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ov3rcl0ck

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Junior Poster

27 Days Ago

open it in binary mode. In unix however binary mode isn't needed but using 'wb' or 'rb' instead of 'w' or 'r' doesn't hurt. This should copy the file contents of a file to another no matter the content:

 Help with Code Tags 
 Python Syntax (Toggle Plain Text) 
fi=open("filein", 'rb').read()
fo=open("fileout",'wb')
fo.write(fi)
fo.close()
fi=open("filein", 'rb').read()
fo=open("fileout",'wb')
fo.write(fi)
fo.close()

In windows you just gotta use the 'rb'/'wb' flags to read the file contents as binary.

NOTE: sudo doesn't apply to real life situations.

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Join Date: Oct 2004

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vegaseat

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DaniWeb's Hypocrite

27 Days Ago

If you read a binary as a text file (mode='r'), you have to be aware that the binary data can inadvertently contain an EOF (End Of File) marker early on, at which point the read would stop. Using a binary read (mode='rb') will prevent this.

Here is a simple way to detect a binary file ...

 Help with Code Tags 
 Python Syntax (Toggle Plain Text) 
# use with Python3
 
def is_binary_file(fname):
    fin = open(fname, "rb")
    data = fin.read()
    fin.close()
    # a typical binary file contains zero value bytes
    if 0 in data:
        print("File %s is binary" % fname)
    else:
        print("File %s is not binary" % fname)
 
# pick a typical binary file like an image file you have
# in the working directory or give the full file path
fname = 'py.ico'
is_binary_file(fname)
 
# pick a text file you have in the working directory
fname = 'Zoomer.txt'
is_binary_file(fname)
# use with Python3

def is_binary_file(fname):
    fin = open(fname, "rb")
    data = fin.read()
    fin.close()
    # a typical binary file contains zero value bytes
    if 0 in data:
        print("File %s is binary" % fname)
    else:
        print("File %s is not binary" % fname)

# pick a typical binary file like an image file you have
# in the working directory or give the full file path
fname = 'py.ico'
is_binary_file(fname)

# pick a text file you have in the working directory
fname = 'Zoomer.txt'
is_binary_file(fname)

If you use Python2 the binary read is different, you have to iterate and use ord().

BTW, thread titles like ...
Can Python do this?
I need help
Help
are meaningless and kind of stupid! Use a tiltle that tells the rest of us what you want.

Last edited by vegaseat; 27 Days Ago at 11:59 am. Reason: titles

May 'the Google' be with you!

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woooee

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Veteran Poster

27 Days Ago

•

Also, is there anyway in Python that you can test whether or not a line of data is binary?

All data is binary. That's the way the computer does it. I am assuming that you mean bytes that are not text. If you look at an ASCII table like this one http://www.asciitable.com/ it becomes apparent that for the English character set you want to check for anything less than decimal 32 (space) or greater than decimal 126 (~). Python uses ord(character) to covert and I don't know of any way other than converting and checking every byte in the file. Post some code and we can help you with problems

•

BTW, thread titles like ...
Can Python do this?
I need help
Help
are meaningless and kind of stupid! Use a tiltle that tells the rest of us what you want.

It takes a large amount of self control not to respond with
Can Python do this? (Who are you, Steve Urkel)
I need help (We all do but most of us can't afford a psychiatrist)
Help (Have you fallen and can't get up?)

Last edited by woooee; 27 Days Ago at 1:02 pm.

Linux counter #99383

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Gribouillis Gribouillis is online now

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Posting Shark

27 Days Ago

•

Originally Posted by woooee

It takes a large amount of self control not to respond with
Can Python do this? (Who are you, Steve Urkel)
I need help (We all do but most of us can't afford a psychiatrist)
Help (Have you fallen and can't get up?)

The answer to "Can Python do this ?" is usually Yes.
"I need help" often means it's homework due in 2 hours.

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Join Date: Oct 2004

Posts: 4,025

Reputation: vegaseat is just really nice

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vegaseat

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DaniWeb's Hypocrite

27 Days Ago

LF and CR are actually printable.

This little code will give you a list of printable characters ...

 Help with Code Tags 
 Python Syntax (Toggle Plain Text) 
import string
 
print( list(string.printable) )
import string

print( list(string.printable) )

Last edited by vegaseat; 25 Days Ago at 11:49 am. Reason: code

May 'the Google' be with you!

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Join Date: Nov 2009

Posts: 70

Reputation: P00dle is an unknown quantity at this point

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P00dle

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Junior Poster in Training

#10

25 Days Ago

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Originally Posted by woooee

All data is binary. That's the way the computer does it. I am assuming that you mean bytes that are not text. If you look at an ASCII table like this one http://www.asciitable.com/ it becomes apparent that for the English character set you want to check for anything less than decimal 32 (space) or greater than decimal 126 (~). Python uses ord(character) to covert and I don't know of any way other than converting and checking every byte in the file. Post some code and we can help you with problems

It takes a large amount of self control not to respond with
Can Python do this? (Who are you, Steve Urkel)
I need help (We all do but most of us can't afford a psychiatrist)
Help (Have you fallen and can't get up?)

I appreciate all the help, guys. Thank you.

I wanted to ask God for a bike, but I know thats not how he does things, so I stole one and asked for forgiveness.