Question

Thanks guys, that really helped. My main problem as you all pointed out was that I had 4 white spaces rather than a tab!

I have a textfile of the format:

string001    124.342
string002    235.111
string003    552.145

With a blank line at the bottom.

I just want to read this into an array. I thought that the best way to do this would be loadtxt from numpy, but when this didn’t work, I went for genfromtxt, but couldn’t quite get it to work either. This is what I have as my latest effort:

y = np.genfromtxt('1400list.txt',delimiter="\t", dtype=[('mystring','S10'),('myint','i8')])

print y

But I get the error:

rows = np.array(data, dtype=[('', _) for _ in dtype_flat])
ValueError: size of tuple must match number of fields.

Could anyone please help me to figure this one out?

Thank you!

Answer 1

Your code works fine here (although I suppose you want to use float dtype instead of integer one) with Python 2.7 and numpy 1.5.1:

#!/usr/bin/env python
import numpy

y = numpy.genfromtxt('1400list.txt', delimiter='\t',dtype=[('A', 'S10'),
('B', 'i8')])
print y

The output is:

vicent@deckard:/tmp$ python prova.py 
[('string001', 124L) ('string002', 235L) ('string003', 552L)]
vicent@deckard:/tmp$

Please, make sure that you are using tabs instead of spaces in your data file.