Python基础教程之增加和去除数字的千位分隔符

input_amount = input()
output_amount = float(input_amount.replace(',',''))
print('去掉千分位后的数字为', output_amount)

# 将数字转为字符串
number = 12345
number_str = str(number)
    
# 拆分成整数部分和小数部分
number_str_list = number_str.split('.')
integer_part = number_str_list[0]
decimal_part = None if len(number_str_list) == 1 else number_str_list[1]

new_integer_part = ''
reversed_integer_part = integer_part[::-1] # 将字符串左右反转
for i, c in enumerate(reversed_integer_part): # 遍历字符，每隔3个字符加逗号
    if i > 0 and i%3 == 0:
        new_integer_part = new_integer_part + ',' + c 
    else:
        new_integer_part += c
new_integer_part = new_integer_part[::-1] # 将字符串左右反转

if decimal_part:
    print('添加千分位后数字变为', new_integer_part + '.' + decimal_part)
else:
    print('添加千分位后数字变为', new_integer_part)

import locale

# empty string for platform's default settings
locale.setlocale(locale.LC_ALL, '')
print(format(4901711, "n")) # -> 4,901,711
print("{:n}".format(4901711)) # -> 4,901,711
print("{:d}".format(4901711)) # 4901711

from decimal import Decimal

print(format(1234567, ',d'))
print('{:,d}'.format(1234567))
print(format(1234567.89, ',.2f'))
print(format(12345.6 + 8901234.12j, ',f'))
print(format(Decimal('1234567.89'), ',f'))