vectorsum.py
#!/usr/bin/env/python
import sys
from datetime import datetime
import numpy as np
# def numpysum(n):
# a = np.arange(n) ** 2
# b = np.arange(n) ** 3
# c = a + b
# return c
def pythonsum(n):
a = range(n)
b = range(n)
c = []
for i in range(len(a)):
a[i] = i ** 2
b[i] = i ** 3
c.append(a[i] + b[i])
return c
size = int(sys.argv[1])
print (size)
start = datetime.now()
c = pythonsum(size)
delta = datetime.now() - start
print ("The last 2 elements of the sum", c[-2:])
print ("PythonSum elapsed time in microseconds", delta.microseconds)
# start = datetime.now()
# c = numpysum(size)
# delta = datetime.now() - start
# print ("The last 2 elements of the sum", c[-2:])
# print ("NumPySum elapsed time in microseconds", delta.microseconds)
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运行结果：
D:\>python vectorsum.py 1000
1000
Traceback (most recent call last):
File "vectorsum.py", line 26, in <module>
c = pythonsum(size)
File "vectorsum.py", line 17, in pythonsum
a[i] = i ** 2
TypeError: 'range' object does not support item assignment
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将pythonsum函数修改如下：
def pythonsum(n):
a = list(range(n))
b = list(range(n))
c = []
for i in range(len(a)):
a[i] = i ** 2
b[i] = i ** 3
c.append(a[i] + b[i])
return c
运行正常，通过
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