如何在f-string中同时格式化字符串和变量？

Question

我想将"$"和totalTransactionCost一起移动到字段的右侧。

我的当前代码是：print(f"所有交易总成本：${totalTransactionCost:>63,.2f}")

该代码能够将totalTransactionCost移动到字段的右侧，但如何同时包含"$"？

- Carson McDowell

Answer 1

您可以使用嵌套的 f-strings，将格式化分为两个步骤：首先，将数字格式化为逗号分隔的两位小数字符串，并附加 $，然后填充整个字符串以获得前导空格。

>>> totalTransactionCost = 10000
>>> print(f"Total Cost Of All Transactions: {f'${totalTransactionCost:,.2f}':>64}")
Total Cost Of All Transactions:                                                       $10,000.00

- Mechanic Pig

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解释会丰富答案。 - semmyk-research

Answer 2

f-string提供了灵活性。
如果货币是由系统确定的，locale允许利用系统的设置：LC_MONETARY表示货币

以下是f-string的演示

## input value or use default
totalTransactionCost = input('enter amount e.g 50000') or '50000'

## OP's code:
#print(f"Total Cost Of All Transactions: ${totalTransactionCost:>63,.2f}")

## f-string with formatting
## :,.2f  || use thousand separator with 2 decimal places
## :>63 || > aligns right with 63 spaces
## :<      || < aligns left
## { ... :,.2f} apply to inner f-string value
## {f'${ ... }':>64}  || apply to outer f-string value

print(f'|Total Cost of All Transactions|: {f"${int(totalTransactionCost):,.2f}":>64}')

## Note that the inner and outer uses different escapes. 
## The order doesn't matter though. Here, inner is " and outer is '.

|enter amount e.g 50000| 750000
Total Cost of All Transactions:                                                      $750,000.00

- semmyk-research