Pythonの知識を共有した9日目

知識を補充する.

1.文字列メソッドの補完

s = str()
s.format() #  
" ".join(" ") #  
s.find() #  
s.capitalize() #  
s.title() #  
s.index("e") #  
s.center(20) #  
s.encode("utf-8") #  
s.swapcase() #  

2.リストメソッドの補足

lst = list()
lst.sort() #  ， 
lst.reverse() #  
lst.sort(reverse=True)  # ， 
print(lst)

3.辞書の書き方の補足

dic = dict()
dic.fromkeys(" "," ") 
#    1： ， 2： 

4.面接でよく出会う穴

#  1
 
lst2 = [1,2,[]]
lst3 = lst2 * 3
print(lst2)
print(lst3)   # [] 
lst3[-1].append(5)
print(lst3)
# lst3[] 5， [] 

 
tu1 = (1,2,[])
tu2 = tu1 * 3
tu2[-1].append(10)
print(tu2)
 [] 

 
dic = {}
dic = dic.fromkeys("abc",[])
print(dic)
dic["a"] = "8"
print(dic)
 "a" 8， 

#  2
 
1.for 
2. 
lst = [1,2,3,4,5,6,7]
for i in range(len(lst)):
    if i % 2 == 1:
        lst.pop(i)
print(lst)
for i in range(len(lst)-1,-1,-1):
    if i % 2 ==1:
        lst.pop(i)
print(lst)
 for ， ， 
 ， ， 

 1
 
lst = [" "," "," "," "," "," "]
lst1 = lst[:]
for i in lst1:
    if i.startswith(" "):
        lst.remove(i)
print(lst)

 :
dic = {"key":1,"key2":2,"key3":4}  #  
for i in dic:
    dic[i] = i
print(dic)

 
dic = {"key":1,"key2":2,"key3":4}
dic1 = dic.copy()
for i in dic1:
    del dic[i]
print(dic)

5.符号化ステップ

s = " "
s1 = s.encode("utf-8")
s2 = s1.decode("utf-8")
print(s2)
print(s.encode("gbk"))