Python String Formatting: % Placeholders vs f‑Strings Explained

The note emphasizes that consistent practice is essential when learning Python from scratch.

It introduces two ways to format strings in Python: using the classic % placeholder syntax and the modern f‑string syntax.

For the % method, the article lists common specifiers: %d for integers, %f for floating‑point numbers, %s for strings, and %.2f to limit a float to two decimal places.

Example variables are defined:

name = "张三"
age = 21
money = 12345.321

Using % formatting, the following statements produce formatted output:

print("我的姓名是:%s,年龄是:%d,收入是:%f" % (name, age, money))
print("我的姓名是:%s,年龄是:%d,收入是:%.2f" % (name, age, money))
print("我的姓名是:%s,年龄是:%d,收入是:%.3f" % (name, age, money))

With f‑strings, the same information is printed more concisely:

print(f"我的姓名是：{name},年龄是{age},收入是{money}")

The article then shows the resulting output for each method, demonstrating that the % approach prints the full float by default, while formatting specifiers can control precision, and that f‑strings produce the same values with simpler syntax.