Function
Source
https://pythonbook.cc/chapters/basic/function
引數
source: https://docs.python.org/3/library/functions.html#sorted
python
sorted(iterable, /, *, key=None, reverse=False)
Return a new sorted list from the items in iterable.
/
前的iterable
一定要用位置引數*
後的key
、reverse
一定要用關鍵字引數- example:python
sorted([9, 5, 2, 7], reverse=True)
參數預設值的坑
source: https://pythonbook.cc/chapters/basic/function#參數預設值
python
def add_to_box(a, b, box=[]):
box.append(a)
box.append(b)
return box
add_to_box(1, 4) # [1, 4]
add_to_box(5, 0) # [1, 4, 5, 0]
可以調整為:
python
def add_to_box(a, b, box=None):
if box is None:
box = []
box.append(a)
box.append(b)
return box
add_to_box(1, 4) # [1, 4]
add_to_box(5, 0) # [5, 0]
lambda
python
add = lambda a, b: a + b
add(1, 2) # 3
Closure
運作原理 source:https://pythonbook.cc/chapters/basic/function-advanced#運作原理