Python | Ways to convert array of strings to array of floats

Last Updated : 26 Feb, 2019

Sometimes in a competitive coding environment, we get input in some other datatypes and we need to convert them in other forms this problem is same as that we have an input in the form of string and we need to convert it into floats.
Let’s discuss a few ways to convert an array of strings to array of floats.

Method #1 : Using astype

# Python code to demonstrate converting 
# array of strings to array of floats
# using astype
  
import numpy as np
  
# initialising array
ini_array = np.array(["1.1", "1.5", "2.7", "8.9"])
  
# printing initial array
print ("initial array", str(ini_array))
  
# conerting to array of floats
# using np.astype
res = ini_array.astype(np.float)
  
# printing final result
print ("final array", str(res))

Output:

initial array ['1.1' '1.5' '2.7' '8.9']
final array [ 1.1  1.5  2.7  8.9]

Method #2: Using np.fromstring

# Python code to demonstrate converting 
# array of strings to array of floats
# using fromstring
  
import numpy as np
  
# initialising array
ini_array = np.array(["1.1", "1.5", "2.7", "8.9"])
  
# printing initial array
print ("initial array", str(ini_array))
  
# conerting to array of floats
# using np.fromstring
ini_array = ', '.join(ini_array)
ini_array = np.fromstring(ini_array, dtype = np.float, 
                                           sep =', ' )
  
# printing final result
print ("final array", str(ini_array))

Output:

initial array ['1.1' '1.5' '2.7' '8.9']
final array [ 1.1  1.5  2.7  8.9]

Method #3: Using np.asarray() and type

# Python code to demonstrate
# converting array of strings to array of floats
# using asarray
  
import numpy as np
  
# initialising array
ini_array = np.array(["1.1", "1.5", "2.7", "8.9"])
  
# printing initial array
print ("initial array", str(ini_array))
  
# conerting to array of floats
# using np.asarray
final_array = b = np.asarray(ini_array, 
        dtype = np.float64, order ='C')
  
# printing final result
print ("final array", str(final_array))

Output:

initial array ['1.1' '1.5' '2.7' '8.9']
final array [ 1.1  1.5  2.7  8.9]

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