I have a problem during the reading of a text file in python. Basically what I need is to get the 4th column in a list.
With this small function I achieve it without any great issues:
def load_file(filename):
f = open(filename, 'r')
# skip the first useless row
line = list(f.readlines()[1:])
total_sp = []
for i in line:
t = i.strip().split()
total_sp.append(int(t[4]))
return total_sp
but now I have to manage files, that in the last row(s) have any random number that don't respect the text format. An example of the not working text file is:
#generated file
well10_1 3 18 6 1 2 -0.01158 0.01842 142
well5_1 1 14 6 1 2 0.009474 0.01842 141
well4_1 1 13 4 1 2 -0.01842 -0.03737 125
well7_1 3 10 1 1 2 -0.002632 0.009005 101
well3_1 1 10 9 1 2 -0.03579 -0.06368 157
well8_1 3 10 10 1 2 -0.06895 -0.1021 158
well9_1 3 10 18 1 2 0.03053 0.02158 176
well2_1 1 4 4 1 2 -0.03737 -0.03737 128
well6_1 3 4 5 1 2 -0.07053 -0.1421 127
well1_1 -2 3 1 1 2 0.006663 -0.02415 128
1 0.9259
2 0.07407
where 1 0.9259 and 2 0.07407 have to be dumped.
In fact, using the function of above with this text file, I get the following error because of the 2 additional last rows:
Traceback (most recent call last):
File "<input>", line 1, in <module>
File "/tmp/tmpqi8Ktw.py", line 21, in load_obh
total_sp.append(int(t[4]))
IndexError: list index out of range
How can I get rid of the last lines in the line variable?
Thanks to all
There are many ways to handle this, one such way can be to handle the indexError by surrounding the erroneous code by try and except, something like this :
try :
total_sp.append(int(t[4]))
except IndexError :
pass
This will only append to the total_sp when index exits otherwise not. Also, this will handle whenever you do not have the data present corresponding to that particular index.
Alternatively, if you are interested in removing just the last two rows (elements), you can use the slice operator such as by replacing line = list(f.readlines()[1:]) with line = f.readlines()[1:-2].