Python read .txt-files header

Question

I need to read some information from a txt file header which looks like this:

Date    20160122
SP Number   8
Gauge   250N internal
Total Height    61
SP Modell   SP2
Corner Distance 150 

Height  Value   Comment
60  NaN 
...

I have a python program program currently doing this:

depth, N = npy.loadtxt(filename, skiprows=8, unpack=True, usecols = usecols)

However I would like to read out some of the values from the header. Is there a way to do this? I am mostly interested to get the value of "Total Height". On my search I only seem to find answers concerning .csv files.

Answer 1

I would use open rather than npy.loadtxt

with open(filename, 'r') as the_file:
    all_data = [line.strip() for line in the_file.readlines()]
    height_line = all_data[3]
    data = all_data[8:]

Then you can parse the value of height_line, to get the Total Height. And all your data from the file will be in the variable data.

Answer 2

This should work!

field = "Total Height"

# Get first 6 lines
with open(filename) as file:
    lines = [next(file) for x in range(6)]

value = None
for line in lines:
    if line.startswith(field):
        # Get the part of the string after the field name
        end_of_string = line[len(field):]

        # Convert it to an int:
        value = int(end_of_string.strip())

print(value) #Should print 61

If you know that the field names and values are separated by a tab character instead of spaces, you could instead use line.split('\t') to break each line into the field name and field value, and then just check if field_name is the field you care about, and if so, use the value, instead of using startswith and then slicing the resulting string to get the end of it.