how to remove the line if it contain the “word”? in python

Question

I have an input file looks like this

test.txt
CAT 396 NUM 59 
X          Y     
4.7642     28.4443    
4.7643     28.3640    
6.2216     29.0680    
6.2217     29.2841    
6.4080     28.6427    
6.6484     28.6484    

CAT 397 NUM 592 
X          Y          
7.0442     23.8320    
7.0994     25.9161    
7.0995     25.1801    

I only need the X and Y coordinate information.

How would I be able to only get the coordinates?

Answer 1

You may try this:

with open('test.txt') as fin :
    lines = fin.readlines()

coords = []
for line in lines :
    try :
        x, y = map( float, line.split())
        coords.append( (x,y) )
    except ValueError:
        pass  # ignore other lines

Answer 2

line = 'some words'
if 'word' in line:
    # skip/delete the line

If the line you want to skip is always first, you can just skip the first line, without checking the words inside it.

Answer 3

You can use readlines()[2:] to skip first two lines and then parse numbers. For example: like this

lines = open('test.txt').readlines()[2:]
coords = []
for line in lines:
    try:
        coords.append(list(map(float, line.split())), lines))
    except ValueError:
        print(f'ValueError in line: {line}')
print(coords)

It returns:

[[7.0442, 23.832], [7.0994, 25.9161], [7.0995, 25.1801]]