5个Python使用F-String进行格式化的实用技巧分享

n = 100000000
print(n)
# 100000000

# 千分位的分隔符用 _ 或者 , 都可以

print(f"{n:_}")
# 100_000_000

print(f"{n:,}")
# 100,000,000

n = 1234.5678
print(f"{n:.2f}")
# 1234.57

print(f"{n:.0f}")
# 1235

print(f"{n:,.3f}")
# 1,234.568

print(f"{n:_.3f}")
# 1_234.568

name = "var"
value = 100

# >20 表示右对齐，并且占用20个字符的空间
print(f"{name:>20}: {value}")

# <20 表示左对齐，并且占用20个字符的空间
print(f"{name:<20}: {value}")

# ^20 表示居中对齐，并且占用20个字符的空间
print(f"{name:^20}: {value}")

# 运行结果
                 var: 100
var                 : 100
        var         : 10

# 下面的例子分别用 _ # | 来占位
print(f"{name:_>20}: {value}")
print(f"{name:#<20}: {value}")
print(f"{name:|^20}: {value}")

# 运行结果
_________________var: 100
var#################: 100
||||||||var|||||||||: 100

from datetime import datetime

now = datetime.now()
print(f"{now:%Y-%m-%d (%H:%M:%S)}")
# 2024-03-12 (00:17:05)

print(f"{now:%c}")
# Tue Mar 12 00:17:05 2024

print(f"{now:%I%p}")
# 12AM

a = 10
b = 20
s = "hello"

print(f"{a + b}")
# 30

print(f"{s}")
# hello

print(f"a + b = {a + b}")
# a + b = 30

print(f"s = {s}")
# s = hello

print(f"{a + b = }")
# a + b = 30

print(f"{s = }")
# s = hello