*****
## 代碼執行時間測量模塊
```
li = []
li.append()
li.insert()
```
### timeit模塊
timeit模塊可以用來測試一小段Python代碼的執行速度。
```
class timeit.Timer(stmt='pass', setup='pass', timer=<timer function>)
Timer是測量小段代碼執行速度的類。
stmt參數是要測試的代碼語句（statment）；
setup參數是運行代碼時需要的設置；
timer參數是一個定時器函數，與平臺有關。
```
timeit.Timer.timeit(number=1000000)
Timer類中測試語句執行速度的對象方法。number參數是測試代碼時的測試次數，默認為1000000次。方法返回執行代碼的平均耗時，一個float類型的秒數。
### list的操作測試
```
def test1():
l = []
for i in range(1000):
l = l + [i]
def test2():
l = []
for i in range(1000):
l.append(i)
def test3():
l = [i for i in range(1000)]
def test4():
l = list(range(1000))
def test5():
li = []
for i in range(1000):
li.insert(0, i)
from timeit import Timer
t1 = Timer("test1()", "from __main__ import test1")
print("add", t1.timeit(number=1000))
t2 = Timer("test2()", "from __main__ import test2")
print("append ",t2.timeit(number=1000))
t3 = Timer("test3()", "from __main__ import test3")
print("list derivation",t3.timeit(number=1000))
t4 = Timer("test4()", "from __main__ import test4")
print("list range ",t4.timeit(number=1000))
t5 = Timer("test5()", "from __main__ import test5")
print("list insert ",t5.timeit(number=1000))
```
