문자열 0 패딩

>>> a = 1
>>> f"{a:01}"
'1'
>>> f"{a:02}"
'01'
>>> f"{a:03}"
'001'

>>> f"{a:10}"
'         1'
>>> f"{a:010}"
'0000000001'

f-string 에서 소수점 자리수 표현

>>> a = 2.341
>>> f"{a:.1f}"
'2.3'
>>> f"{a:.2f}"
'2.34'
>>> f"{a:.3f}"
'2.341'

시간 문자열 조작

def decode_time(data):
    h = data // (3600 * 1000)
    m = (data - h * (3600 * 1000)) // (60 * 1000)
    s = (data - h * (3600 * 1000) - m * (60 * 1000)) // 1000
    ms = (data - h * (3600 * 1000) - m * (60 * 1000) - s * 1000)
    return f"{h:02}:{m:02}:{s:02}.{ms:03}"


def encode_time(data):
    h, m, s, ms = data[:2], data[3:5], data[6:8], data[9:]
    return int(ms) + (int(s) + int(m) * 60 + int(h) * 3600) * 1000
    
a = "01:00:04.001"
print(a) # 01:00:04.001
print(encode_time(a)) # 3604001
print(decode_time(encode_time(a))) # 01:00:04.001