Consulting - Quality
Difference makes the DIFFERENCE
FILE HANDLING
from PadhAI Class
File Handling¶
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import numpy as np
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planets_small = np.loadtxt("planets_small.txt")
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planets_small = np.loadtxt("planets_small.txt", skiprows=1)
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planets_small = np.loadtxt("planets_small.txt",
skiprows = 1,
usecols = (1,2,3,4,5,6,7,8,9))
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planets_small
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planets_small.ndim
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planets_small.shape
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planets = np.loadtxt("planets.txt", skiprows = 1,
usecols = (1,2,3,4,5,6,7,8,9))
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planets = np.genfromtxt("planets.txt", skip_header = 1,
usecols = (1,2,3,4,5,6,7,8,9))
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planets #the previous conversion error "UNKNOWN" is taken care here and
#doesnot return error.
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planets.shape
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planets.isnan()
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np.isnan(planets) # returns false where ever there is an nan
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to convert "NAN" to numpy readable formats or other chosen value => here as -1
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planets_new = np.nan_to_num(planets, nan=-1)
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planets_new
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Save into a file into a human readable format
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np.savetxt('planets_new.txt', planets_new, delimiter=",")
- Save a file in numpy readable format, which is more efficient and less disk space consuming
- file is saved in .npy format
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np.save("planets_new", planets_new)
list files in the default container with ls command with ! command - to run native unix commands
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!ls
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!ls -l
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!ls -lh
to store multiple arrays in the same file
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arr1 = np.random.rand(1000, 10)
arr2 = np.random.rand(2000, 20)
arr3 = np.random.rand(10, 10000)
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np.savez("many_arrs", arr1, arr2, arr3)
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!ls -lh
loading files
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arrs = np.load("many_arrs.npz")
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arrs.files
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arrs['arr_1'].shape
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np.savez_compressed("many_arrs_compressed", arr1, arr2, arr3)
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!ls -lh
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npZeros = np.zeros((10000, 10000))
np.savez_compressed("npZeros_compressed", npZeros)
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np.savez("npZeros", npZeros)
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ls - lh
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!ls -lh
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