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Reading columns from a text file – fast and easy!
Although the are many information on how to use the genfromtxt (from numpy) there is not a clear demonstration (that I found…) to show how to easily read a text file with columns of data (including strings – it is straightforward to read columns of numbers with loadtxt for example).
Suppose that we have the following text file (named ‘input.txt’):
#object q1 q2 id-001 120. 2212. id-002 145. 1222. id-222 123. 1142.
Then we can just use:
g = genfromtxt('input.txt',dtype=None,names=True)
This will read all the file. dtype=None means that the command will decide what type of data is each element and name=True means that we can use the names from the first raw (header) to call each column, i.e.:
print g['object']
print g['q2']
will print:
['id-001' 'id-002' 'id-222']
[ 2212. 1222. 1142.]
That easy, that fast !
