一些好用的函式或方法
阿新 • • 發佈:2022-11-29
一、zip
zip函式可以把兩個函式壓縮在一起,然後返回一個內含元組的列表。如果兩個序列不等長,當最短的序列用完時就會停止。
示例程式碼:
names = ['dnfag','anne','damon','Jhon','David'] ages = [20,25,30,35,40,45] for name,age in zip(names,ages): print(f'{name} is {age} years old')
返回結果:
dnfag is 20 years old
anne is 25 years old
damon is 30 years old
Jhon is 35 years old
David is 40 years old
二、enumerate
enumerate函式可以獲取列表對應的索引和元素:
示例程式碼:
names = ['dnfag','anne','damon','Jhon','David'] for index,name in enumerate(names): print(index,name)
返回結果:
0 dnfag
1 anne
2 damon
3 Jhon
4 David
enumerate函式用於字典時也可以獲取到字典的key及對應的索引,而且是按原來的順序排列好的,如果想按字典的原順序讀取資料,這個還是有用處的:
names = {'dnfag':20,'anne':25,'damon':30,'Jhon':35,'David':40} for index,name in enumerate(names): print(index,name) print(name,names[name])
返回結果:
0 dnfag
dnfag 20
1 anne
anne 25
2 damon
damon 30
3 Jhon
Jhon 35
4 David
David 40
三、isinstance
isinstance 用來判斷一個物件是否是一個已知的型別。函式返回值是布林值。若物件的型別是已知型別,那麼就返回True.否則返回False.用法:
isinstance(物件,物件型別)
物件型別有:int,float,bool,str,list,turple,set,dict
物件型別可以有多個,只要一個符合就返回True.如:
a = "abc" isinstance(a,(int,str,float))
會返回True