[Python]range 함수 예제

range 함수의 기초

# range(start, stop, step) takes three arguments.

# 방법1
print(list(range(30, -12, -2)))

# 방법2
result1 = []
for i in range(30, -12, -2):
    result1.append(i)
print(result1)    

# 방법3
result2 = []
i = 30
while i >= -10:
    result2.append(i)
    i -= 2
print(result2)   

## 결과
[30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10]
[30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10]
[30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10]과

range 함수 심화

# 방법1
result = []
for i in range(1, 21):
    if i % 2 == 1:
        result.append(i * 10)
    else:
        result.append(i)
print(result)


# 방법2 : List Comprehension
result2 = [x * 10 if x % 2 == 1 else x for x in range(1, 21)]
print(result2)


# 기타
print([[y for y in range(5)] for x in range(5)])

## 결과
[10, 2, 30, 4, 50, 6, 70, 8, 90, 10, 110, 12, 130, 14, 150, 16, 170, 18, 190, 20]
[10, 2, 30, 4, 50, 6, 70, 8, 90, 10, 110, 12, 130, 14, 150, 16, 170, 18, 190, 20]
[[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]]

range, map, lambda 동시사용

# 방법1
result = []
for i in range(1, 16):
    result.append(str(i * 10))
print(result)     

# 방법2
print(list(map(lambda x: str(x * 10), range(1, 16))))

# 방법3
print(list([str(x * 10) for x in range(1, 16)]))


## 결과
['10', '20', '30', '40', '50', '60', '70', '80', '90', '100', '110', '120', '130', '140', '150']
['10', '20', '30', '40', '50', '60', '70', '80', '90', '100', '110', '120', '130', '140', '150']
['10', '20', '30', '40', '50', '60', '70', '80', '90', '100', '110', '120', '130', '140', '150']