# others - 在 python 中，初始化一个固定大小的数组

``````
int x[5];/* declared without adding elements*/

``````

``````
>>> lst = [None] * 5
>>> lst
[None, None, None, None, None]

``````

``````
from numpy import ndarray

a = ndarray((5,),int)

``````

``````
a = numpy.empty(n, dtype=object)

``````

``````
Object[] a = new Object[n];

``````

``````
>>> n = 5 #length of list
>>> list = [None] * n #populate list, length n with n entries"None"
>>> print(list)
[None, None, None, None, None]

>>> list.append(1) #append 1 to right side of list
>>> list = list[-n:] #redefine list as the last n elements of list
>>> print(list)
[None, None, None, None, 1]

>>> list.append(1) #append 1 to right side of list
>>> list = list[-n:] #redefine list as the last n elements of list
>>> print(list)
[None, None, None, 1, 1]

>>> list.append(1) #append 1 to right side of list
>>> list = list[-n:] #redefine list as the last n elements of list
>>> print(list)
[None, None, 1, 1, 1]

``````

``````
>>> n = 5 #length of list
>>> list = [] # create list
>>> print(list)
[]

>>> list.append(1) #append 1 to right side of list
>>> list = list[-n:] #redefine list as the last n elements of list
>>> print(list)
[1]

``````

``````
>>> list.append(1) #append 1 to right side of list
>>> list = list[-n:] #redefine list as the last n elements of list
>>> print(list)
[1,1,1,1]

``````

5 和所有后续：

``````
>>> list.append(1) #append 1 to right side of list
>>> list = list[-n:] #redefine list as the last n elements of list
>>> print(list)
[1,1,1,1,1]

``````

``````
t = input("")
x = [None]*t
y = [[None]*t]*t

for i in range(1, t+1):
x[i-1] = i;

for j in range(1, t+1):
y[i-1][j-1] = j;

print x
print y

``````

``````
2
[1, 2]
[[1, 2], [1, 2]]

``````

``` ```
x = [0]*10

``` ```

``````
class fixedSizeArray(object):
def __init__(self, arraySize=5):
self.arraySize = arraySize
self.array = [None] * self.arraySize

def __repr__(self):
return str(self.array)

def __get__(self, instance, owner):
return self.array

def append(self, index=None, value=None):
print"Append Operation cannot be performed on fixed size array"
return

def insert(self, index=None, value=None):
if not index and index - 1 not in xrange(self.arraySize):
print 'invalid Index or Array Size Exceeded'
return
try:
self.array[index] = value
except:
print 'This is Fixed Size Array: Please Use the available Indices'

arr = fixedSizeArray(5)
print arr
arr.append(100)
print arr
arr.insert(1, 200)
print arr
arr.insert(5, 300)
print arr

``````

``````
[None, None, None, None, None]
Append Operation cannot be performed on fixed size array
[None, None, None, None, None]
[None, 200, None, None, None]
This is Fixed Size Array: Please Use the available Indices
[None, 200, None, None, None]

``````

``````
import numpy as np

x= np.zeros(5,str)
print x

``````

``````
['' '' '' '' '']

``````

``````
>>> import numpy
>>> x = numpy.zeros((3,4))
>>> x
array([[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.]])
>>> y = numpy.zeros(5)
>>> y
array([ 0., 0., 0., 0., 0.])

``````

``````
with open(FILENAME, 'rb') as f:
data = bytearray(os.path.getsize(FILENAME))