Python循环从文件的每一行获取数据并将其转换为dec

Question

I'm kinda lost at the moment: I have text file with lines looking like that:

/dev/input/event0: 0003 0035 000002ac 
/dev/input/event0: 0003 0036 000008fb

There are many lines like that, and I want to make script that gets the last hex value from every line and then writes them in file with output looking like this:

something someting hex_from_line_1 hex_from_line_2 
something someting hex_from_line_3 hex_from_line_4 

And so on. As I'm new to Python I have some trouble with making loop which would do this. Can You give me any guidance? (I'm not asking for whole loop, only guidance - I'd love to learn that, not use some finished code)

Answer 1

A fun thing about Python's zip is that it will happily take the same iterator multiple times as arguments, allowing you to pair up inputs easily. For example:

# For efficiency, if you're on Python 2, include this line so zip is a generator that produces pairs on demand, rather than eagerly slurping the whole file
from future_builtins import zip

with open('myinput') as f:
    # Creates a generator that produces only the final space separated value for each line (could be anything; not checking for hex)
    final_hex = (line.rsplit(None, 1)[-1] for line in f)
    # By using the same generator twice, we get the 1st, 3rd, 5th, etc. from one
    # and the 2nd, 4th, 6th, etc. from the other.
    for hexa, hexb in zip(final_hex, final_hex):
        print("something something", hexa, hexb) # Python 3 print function
        print "something something", hexa, hexb  # Python 2 print statement

Note: If the input data isn't an even number of lines, this will drop the final unpaired input. You can use itertools.zip_longest ( izip_longest on Python 2) if you want the unpaired value.

Answer 2

I'm kinda lost at the moment: I have text file with lines looking like that: /dev/input/event0: 0003 0035 000002ac /dev/input/event0: 0003 0036 000008fb There are many lines like that, and I want to make script that gets the last hex vaule from every line and then writes them in file with output looking like this: something someting hex_from_line_1 hex_from_line_2 something someting hex_from_line_3 hex_from_line_4 And so on. As I'm new to Python I have some trouble with making loop which would do this. Can You give me any guidance? (I'm not asking for whole loop, only guidance - I'd love to learn that, not use some finished code)

Loop over the lines in the file like this

with open('filename.txt','r') as f:
    for line in f:
        hexNibble=line[-1] #this is a string
        hexValue=int(hexNibble,16) #this is an integer
        #Now you have the integer value of the last hex nibble on the line
        #So...
        #Continue doing whatever you want to do with it...

Answer 3

file.txt

/dev/input/event0: 0003 0035 000002ac 
/dev/input/event0: 0003 0036 000008fb
/dev/input/event0: 0003 0035 000002ad 
/dev/input/event0: 0003 0036 000008fe
/dev/input/event0: 0003 0035 000002af 
/dev/input/event0: 0003 0036 000008fg
/dev/input/event0: 0003 0036 000008fz

code

with open('file.txt', 'rb') as f:
    data = [x.split(': ')[1].strip() for x in f.read().splitlines()]

with open('output.txt', 'wb') as f:
    for i in range(0, len(data), 2):
        f.write('something something {0}\n'.format(' '.join(data[i:i+2])))