Hi all, Thanks to Hans, I have had a good progress on my problem.
Followings are Hans's Idea: import numpy as np b = [] c = 4 f = open("text.file", "r") while c < 10: c = c + 1 f.seek(0,0) for columns in ( raw.strip().split() for raw in f ): b.append(columns[c]) y = np.array(b, float) print c, y It's a bit inefficient to read the same file several times. You might consider reading it just once. For example: import numpy as np b = [] f = open("text.file", "r") data = [ line.strip().split() for line in f ] f.close() for c in xrange(5, 11): for row in data: b.append(row[c]) y = np.array(b, float) print c, y ------------------------------------------------------------------------------- It is a great idea, but I found some problems. I want each individual array of y. However, these two codes prodce accumulated array such as [1,2,3], [1,2,3,4,5,6], [1,2,3,4,5,6,7,8,9] and so on. I have tried to initialize for loop for each time to produce array. This effort has not been very successful. Do you guys have any idea? I will really appreciate ant help and idea. Thanks, Isaac -- http://mail.python.org/mailman/listinfo/python-list