

In [ ]:

    
from IPython.display import display_pretty
import numpy as np
from io import StringIO, BytesIO

I/O with numpy

importing data with genfromtext

spliting lines into columns
skiping lines and choose columns
choosing the data type
setting the names
tweaking the conversion
Using missing and filling values



In [ ]:

    
data = '''
c1, c2, c3
1, 2, 3
// here is the comment line
4, 5, 6
7,8,9
-1, -1, -1
end, end, end
'''.encode()
a = np.genfromtxt(BytesIO(data), delimiter=',', comments='//')
b = np.genfromtxt(BytesIO(data), delimiter=',', dtype='|S5', autostrip=True, comments='//')
c = np.genfromtxt(BytesIO(data), delimiter=',', comments='//', skip_header=2, skip_footer=1)
d = np.genfromtxt(
    BytesIO(data),
    delimiter=',',
    comments='//',
    skip_header=1, skip_footer=1,
    names=True,
    usecols=('c1', 'c3'))
e = np.genfromtxt(
    BytesIO(data), delimiter=',', autostrip=True, comments='//',
    skip_header=2, skip_footer=1,
    converters={0: lambda x: float(x) ** 2})
display_pretty(a, b, c, d, e)