[Python] Repl.it - if/else/for문/print()

https://snakify.org/lessons/if_then_else_conditions/

- if/else

 

x = int(input()) if x > 0:     print(x) else:     print(-x)

- abs() : 절댓값

x = int(input()) print(abs(x)) // 절댓값.  input : 10 / output : 10 input : -10 / output : 10

- bool

print(bool(-10))    # True print(bool(0))      # False - zero is the only false number print(bool(10))     # True print(bool(''))     # False - empty string is the only false string print(bool('abc'))  # True

- or

a = int(input()) b = int(input()) if a % 10 == 0 or b % 10 == 0:     print('YES') else:     print('NO')

- and not

if a > 0 and not (b < 0):

- elif

x = int(input()) y = int(input()) if x > 0 and y > 0:     print("Quadrant I") elif x > 0 and y < 0:     print("Quadrant IV") elif y > 0:     print("Quadrant II") else:     print("Quadrant III")

- 변수 위치

if else 안에서 처음 선언해도 if else 밖에서 그 변수 사용 가능!

- 윤년문제

a = int(input()) if a % 400 == 0: print("LEAP") else: //오오   if a % 4 == 0:     if a % 100 == 0: print("COMMON")     else: print("LEAP")   else:     print("COMMON")

https://snakify.org/lessons/for_loop_range/

- for문

for character in 'hello':     print(character)

//output 

h

e 

l 

l 

o

for i in range(5, 8):     print(i, i ** 2)

//output

5 25

6 36

7 49

for i in range(3):     print(i)

0

1

2

for i in range(2 ** 2):     print('Hello, world!')

Hello, world!

Hello, world!

Hello, world!

Hello, world!

# Range() can define an empty sequence, like range(-5) or range(7, 3). In this case the for-block won't be executed

for i in range(-5):     print('Hello, world!') for i in range(7, 3): ~~

none

# range(start_value, end_value, step)

for i in range(10, 0, -2):     print(i)

10

8

6

4

2

// 0은 출력 안됨

- 그냥 print() : \n 개행

- 끝에 조건 달기

print(1, 2, 3) print(4, 5, 6) print(1, 2, 3, sep=', ', end='. ') print(4, 5, 6, sep=', ', end='. ') print() print(1, 2, 3, sep='', end=' -- ') print(4, 5, 6, sep=' * ', end='.')

1 2 3

4 5 6

1, 2, 3. 4, 5, 6. 

123 -- 4 * 5 * 6.

?? line 1, 2는 개행됐는데 line 3, 4는 개행 안됨,,

- 예제

for i in range(a, b - 1, -1): //a = 8, b = 5     print(i)

위처럼 b - 1을 해줘야 8 7 6 5가 출력됨 (8, 4, -1) => 8 7 6 5