def my_range(start, end=none, step=1):
result =
beg = none
if end == none:
beg = 0
final = start-1
else:
beg = start
if step >0:final = end-1
else: final = end+1
if step > 0:
while beg<=final:
yield beg
beg +=step
elif step < 0:
while final<=beg:
yield beg
beg +=step
else:
raise baseexception("step not allow 0")
for i in my_range(-1,-1):
print(i)
class myrange:
def __init__(self, start, stop=none, step=none):
# 模擬range從0開始的行為
if stop is none:
self.start = 0
self.stop = start - 1
else:
self.start = start
self.stop = stop - 1
self.step = step
# 保留原始引數
self.origin_start = self.start
self.origin_stop = self.stop + 1
self.origin_step = self.step
def __repr__(self):
""":return: 顯示表現
"""if self.origin_step:
result = '{}({}, {}, {})'.format(
self.__class__.__name__,
self.origin_start,
self.origin_stop,
self.origin_step
)else:
result = '{}({}, {})'.format(
self.__class__.__name__,
self.origin_start,
self.origin_stop
)return result
def __iter__(self):
return self
def __next__(self):
""":return: 返回當前數字，然後在當前數字上+1
"""result = self.start
if self.start <= self.stop:
self.start += 1
else:
raise stopiteration
return result
def __getitem__(self, item):
""":param item: 如果是單個數字, 那麼item的型別將會是int,
如果是分片那麼item將會是乙個slice.
:return: 返回分片結果
"""def is_index_error(_start):
if _start > self.stop:
raise indexerror('分片不得大於最大值.')
if isinstance(item, int):
result = self.origin_start + item
is_index_error(result)
elif isinstance(item, slice):
start = self.origin_start + item.start
stop = self.origin_start + item.stop
list(map(is_index_error, myrange(start, stop)))
result = myrange(start, stop)
else:
raise keyerror
return result
Python range 函式用法
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Python range 函式用法
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Python range 函式用法
python range 函式用法 python 內建函式 python 內建函式 python range 函式可建立乙個整數列表，一般用在 for 迴圈中。函式語法 range start,stop step 引數說明 start 計數從 start 開始。預設是從 0 開始。例如range 5...