python第一次作业

# 1、使用while循环输入 1 2 3 4 5 6     8 9 10

i = 1
while i < 11:
    if i!= 7:
        print(i)
    else:
        pass
    i+=1

# 2、求1-100的所有数的和

i = 1
sum = 0
for i in range(1,101):
    i = i+sum
    sum = 0+i
print(sum)

# 3、输出 1-100 内的所有奇数

for i in range(1,101):
    if i%2 == 1:
        print(i)
    i = i+1

# 4、输出 1-100 内的所有偶数

i = 1
while i < 101:
    if i%2 == 0:
        print(i)
    i +=1

# 5、求1-2+3-4+5 ... 99的所有数的和

sum_i = 1
for i in range(1,101):
    if i%2 == 1:
        #print(i)
        sum_i = sum_i + i
    i = i+1
#print(sum_i)
j = 1
sum_j = 2
while j < 101:
    if j%2 == 0:
        #print(j)
        sum_j = sum_j +j
    j = j+1
sum = sum_i - sum_j
print("1-2+3-4+5 ... 99的所有数的和是{}".format(sum))
print("1-2+3-4+5 ... 99的所有数的和是%s"%(str(sum)))
print("1-2+3-4+5 ... 99的所有数的和是{0}".format(sum))
print("1-2+3-4+5 ... 99的所有数的和是{sum}".format(sum = sum))

# 6、用户登陆（三次机会重试）

count = 0
sum = 2
username = "XF"
password = "123456"
while count < 3:
    usr = str(input("请输入账号：")).strip()
    psd = str(input("请输入密码：")).strip()
    if usr == username and psd == password:
        print("登录成功")
        break
    elif usr == username and psd != password:
        sum = sum - count
        print("密码错误,还有%s次输入机会"%sum)
    elif usr != username and psd == password:
        sum = sum - count
        print("无此账号,还有%s次输入机会"%sum)
    elif usr != username and psd != password:
        sum = sum - count
        print("账号名或密码错误，还有%s次输入机会"%sum)
    count = count+1