python3.6的字符串处理f-string的使用技巧分享

name = "鳄鱼儿"
print(f"{name:>20}")
print(f"{name:<20}")
print(f"{name:^20}")

#                 鳄鱼儿
#鳄鱼儿
#        鳄鱼儿

a = 123.456

# 只指定width
print(f"{a:10}")
#'   123.456'

# 指定0width
print(f"{a:010}")
#'000123.456'

# 使用width.precision
print(f"{a:10.1f}")
#'     123.5'
print(f"{a:.2f}")
#'123.46'

number = 15

# 十六进制转换
print(f"hex: {number:#0x}")
# hex: 0xf

# 二进制转换
print(f"binary: {number:b}")
# binary: 1111

# 八进制转换
print(f"octal: {number:o}")
# octal: 17

# 科学计数法
print(f"scientific: {number:e}") 
# scientific: 1.500000e+01

a = 1000000 
print(f"{a= :,}") 
# a= 1,000,000

per = 0.59596
print(f"{per = :.2%}")
# per = 59.60%

a = 1
b = 2

print(f"a = {a}, b = {b}")
# a = 1, b = 2
print(f"{a = }, {b = }")  
# a = 1, b = 2

print(f"{a * b = }")
# a * b = 2

import datetime

today = datetime.datetime.utcnow()
print(f"datetime : {today}")
# datetime : 2024-02-28 06:11:04.848944

print(f"date time: {today:%m/%d/%Y %H:%M:%S}") # 没有微秒
# date time: 02/28/2024 06:11:04

print(f"date: {today:%m/%d/%Y}") # 仅日期
# date: 02/28/2024

print(f"time: {today:%H:%M:%S.%f}") # 仅时间
# time: 06:11:04.848944

print(f"time: {today:%H:%M:%S %p}") # 时间带上上午/下午
# time: 06:11:04 AM

print(f"time: {today:%H:%M}") # 24小时制时间
# time: 06:11

print(f"locale appropriate: {today:%c}") # 本地的适当日期和时间表示法
# locale appropriate: Wed Feb 28 06:13:35 2024

print(f"weekday: {today:%A}") # 获取当前日期是星期几
# weekday: Wednesday

print(f"day of year: {today:%j}") # 获取当前日期是一年中的第几天
# day of year: 059

day_of_year = f"{today:%j}" 
print(f"progress % year: {int(day_of_year)/365 * 100:.2f}%")# 获取本年度已过去时间（百分比）
# progress % year: 16.16%