while 循环

# 简单理解为循环版的if语句
i = 0
while i < 10:
    print(i)
    i += 1

1~100的立方和

i = 1
s = 0
while i <= 100:
    s += i ** 3
    # print(s)
    i = i + 1

print(s)

斐波那契数列的第n项

n = int(input())
a = 1
b = 1
i = 3
while i <= n:
    a, b = b, a + b
    i = i + 1

print(b)

for 循环

(1):遍历字符串中的每个字符

for i in "Python":
    print(i, end=' ')

print()

s = 'AcWing'
for i in s:
    print(i, end=' ')

(2)和range函数搭配

# range(x): 返回0 ~ x-1 的数列
for i in range(10):
    print(i, end=' ')

print()

# range(x,y): 返回 x x+1 x+2 ... y-2 y-1 的数列
for i in range(-2, 10):
    print(i, end=' ')

print()

# range(x,y,z)
# z > 0: 返回 x ~ y-1 的公差为z的等差数列
for i in range(-2, 10, 2):
    print(i, end=' ')

print()

# z < 0: 返回 y+1 ~ x 的公差为z的等差数列
for i in range(9, -2, -1):
    print(i, end=' ')

1~100 的立方和

s = 0
for i in range(1, 101):
    s = s + i ** 3

print(s)

斐波那契第n项

a, b = 1, 1
n = int(input())
for i in range(1, n):
    a, b = b, a + b
print(a)

break 和 continue

判断质数

n = int(input())
falg = True
if n == 1: falg = False
for i in range(2, n):
    if n % i == 0:
        falg = False
        break
if falg:
    print("Yes")
else:
    print("No")

求 1 ~ 100 中所有偶数的和

S = 0
for i in range(1, 101):
    if i % 2 !=0: continue
    S += i
print(S)