NumPy 문자열을 숫자로 변환

1 개요

NumPy 문자열을 숫자로 변환

2 숫자문자열

2.1 방법 1: astype() ★

import numpy as np
a = np.array(['1.1', '2.2', '3.3'])
b = a.astype(np.float)
print( b )
print( type(b[0]) )

2.2 방법 2: np.asarray()

import numpy as np
a = np.array(['1.1', '2.2', '3.3'])
b = np.asarray(a, np.float)
print( b )
print( type(b[0]) )

2.3 방법 3: np.asfarray()

import numpy as np
a = np.array(['1.1', '2.2', '3.3'])
b = np.asfarray(a, float)
print( b )
print( type(b[0]) )

3 alphanum 문자열

import numpy as np
import re
a = np.array(['item1', 'item2', 'item3'])
b = np.vectorize(lambda x: int(re.search(r"[0-9]+", x).group(0)))(a)
print( b )
print( type(b[0]) )

import numpy as np
import re
a = np.array(['apple1.1', 'banana2.2', 'lemon3.3'])
b = np.vectorize(lambda x: float(re.search(r"[0-9.]+", x).group(0)))(a)
print( b )
print( type(b[0]) )

import numpy as np
import re
a = np.array([['item111',1,'order1001'],['item222',1,'order1001'],['item333',2,'order1002']])
b = np.vectorize(lambda x: int(re.search(r"[0-9.]+", x).group(0)))(a)
print( b )
print( type(b[0][0]) )

import numpy as np
import re
a = np.array([['item111',1,'order1001'],['item222',1,'order1001'],['item333',2,'order1002']])
b = np.vectorize(lambda x: float(re.search(r"[0-9.]+", x).group(0)))(a)
print( b )
print( type(b[0][0]) )

4 같이 보기

• NumPy astype()
• NumPy asarray()
• NumPy asfarray()
• NumPy vectorize()

5 참고

• https://stackoverflow.com/questions/3877209/how-to-convert-an-array-of-strings-to-an-array-of-floats-in-numpy