①s[:4]          ②s[-5：-1]         ③s[:2]+s[3]*2        ④s[0:2]+s[3:5]

s1="today"

s2=""

for c in s1:

    s2=c+s2

print(s2)

x=0

for i in range(1,11,2):

    x+=i

print(x)

s="Good-Luck-2023!"

n=0;m=0;k=0

for i in range(len(s)):

    ch=s[i]

    if ch>="0" and ch<="9":

        m=m+1

    elif ch>="a" and ch<="z":

        n=n+1

    else:

        k=k+1

a= int(input("請輸入整數(shù)a:"))

b= int(input("請輸入整數(shù)b:"))

s=0

for i in     ①    :

    if     ②    :

        s=s+i

print("[" ,a, b,"]區(qū)間內(nèi)的奇數(shù)和為:",s)

程序中劃線①處應(yīng)填入的代碼為

程序中劃線②處應(yīng)填入的代碼為

count = 0

for i in range(100,991,10) :

    a=i//100

    b=   ①    

    if a==3 or b==3 :

            ②   

        print(i)

print("符合條件的數(shù)共有：",count,"個(gè)")

程序中劃線①處應(yīng)填入的代碼為

程序中劃線②處應(yīng)填入的代碼為

s=input("請輸入一串整數(shù)，以逗號間隔開來:")

t=""

sum=0

for i in    ①   :

    if i!=", ":

            ②  

    else:

        sum=sum+int(t)

        t=""

print("該數(shù)據(jù)序列的和為:",sum)