ตัวแปลงชนิด: int, float, string, path

Captured values default to strings, but /post/42 should give a number, not text. A converter tells Flask what type to expect in that segment.

Put the converter name before the variable with a colon. The pattern is <converter:name>, and Flask applies it before calling your view.

Use int to capture whole numbers. /post/42 hands your view the integer 42, so you can do math without calling int() yourself. 🔢

A converter also filters URLs. /page/abc will not match an int route, so Flask returns 404 instead of crashing inside your function.

Use float for decimal numbers like prices or ratings. /rate/4.5 gives you the float 4.5, ready for arithmetic right away.

string is the default: it accepts any text but stops at a slash. You rarely write it explicitly since plain <name> already behaves this way.

Use path when the value can contain slashes, like a folder route. Unlike string, it captures /docs/intro/setup as one whole value.

Match the converter to your data: int for ids, float for decimals, string for words, path for slashed routes. The right choice prevents bad input early.

By rejecting mismatched URLs with a 404, converters act as a first line of validation. Your view only runs when the type already fits.

You can mix converters across segments. Here an int id and a string tab live in the same path, each typed independently.

The built-in int converter matches only non-negative whole numbers by default. For minus signs or stricter rules, you would write a custom converter later.

Which converter lets a captured value include slashes, like docs/intro/setup?

Converters give captured values a type and reject bad input with a 404. Remember int, float, string, and path. Next: building URLs safely. 🧭