Text Processingflags: m

Python Import Statement

Match Python `import x` and `from x import y` statements, capturing the module and target.

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("^(?:from\\s+([\\w.]+)\\s+)?import\\s+([\\w.,\\s\\*]+?)(?:\\s+as\\s+\\w+)?$", "m");
const input = "import os\\nfrom collections import defaultdict";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"^(?:from\s+([\w.]+)\s+)?import\s+([\w.,\s\*]+?)(?:\s+as\s+\w+)?$", re.MULTILINE)
input_text = "import os\nfrom collections import defaultdict"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`(?m)^(?:from\s+([\w.]+)\s+)?import\s+([\w.,\s\*]+?)(?:\s+as\s+\w+)?$`)
	input := `import os\nfrom collections import defaultdict`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.

Pattern

regexengine-agnostic

^(?:from\s+([\w.]+)\s+)?import\s+([\w.,\s\*]+?)(?:\s+as\s+\w+)?$   (flags: m)

Raw source: ^(?:from\s+([\w.]+)\s+)?import\s+([\w.,\s\*]+?)(?:\s+as\s+\w+)?$

How it works

(?:from\s+([\w.]+)\s+)? optionally matches `from <module>` and captures the module path (group 1). import\s+ requires the import keyword. ([\w.,\s\*]+?) captures the imported names (lazy so the optional `as` alias doesn't get sucked in). (?:\s+as\s+\w+)? optionally matches an alias. The m flag lets ^/$ anchor per line in a multi-line file.