CODEWITHSUNDEEP
pythonpython-3.x
user133140
user133140

Reputation: 169

How to read text file into np.array?

The text data is like the following:

a1  1  2  3  4  5  6  7  8  9  10
b2  2  3  4  5  6  7  8  9  10  11
c3  3  4  5  6  7  8  9  10  11  12
d4  4  5  6  7  8  9  10  11  12  13
e5  5  6  7  8  9  10  11  12  13  14
f6  6  7  8  9  10  11  12  13  14  15
g7  7  8  9  10  11  12  13  14  15  16
h8  8  9  10  11  12  13  14  15  16  17
i9  9  10  11  12  13  14  15  16  17  18
j10  10  11  12  13  14  15  16  17  18  19

How can I read this text file into np.array without the first column (the first column is the name of each row)? Many thanks.

PS. I tried np.loadtxt("filename") and got " could not convert string to float: b'a' " error

Upvotes: 1

Views: 10898

Answers (2)

Siddharth
Siddharth

Reputation: 536

np.loadtxt should work as long as you know the number of columns.

>>> a = np.loadtxt("file_name", usecols=range(1,11), dtype=np.float32)
>>> a
array([[  1.,   2.,   3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.],
       [  2.,   3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.,  11.],
       [  3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.,  11.,  12.],
       [  4.,   5.,   6.,   7.,   8.,   9.,  10.,  11.,  12.,  13.],
       [  5.,   6.,   7.,   8.,   9.,  10.,  11.,  12.,  13.,  14.],
       [  6.,   7.,   8.,   9.,  10.,  11.,  12.,  13.,  14.,  15.],
       [  7.,   8.,   9.,  10.,  11.,  12.,  13.,  14.,  15.,  16.],
       [  8.,   9.,  10.,  11.,  12.,  13.,  14.,  15.,  16.,  17.],
       [  9.,  10.,  11.,  12.,  13.,  14.,  15.,  16.,  17.,  18.],
       [ 10.,  11.,  12.,  13.,  14.,  15.,  16.,  17.,  18.,  19.]])

Upvotes: 5

fstop_22
fstop_22

Reputation: 1032

import numpy as np

b = []
with open('data.txt') as infile:
    lines = infile.readlines()
    for line in lines:
        for n in line.split()[1:]:
            b.append(int(n))
c = np.array(b)

Upvotes: 0

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