fix "Possible nested set" warning

minrk · minrk · commit 17d7afb1243e · 2019-02-21T11:01:38.000+01:00
`[:xdigit:]` is not a valid character class in Python regular expressions

use explicit hex digit pattern
diff --git a/repo2docker/utils.py b/repo2docker/utils.py
@@ -209,7 +209,7 @@ def is_valid_docker_image_name(image_name):
 
         (?::([\w][\w.-]{0,127}))?    # optional capture <tag-pattern>=':<tag>'
         # optionally capture <digest-pattern>='@<digest>'
-        (?:@[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,})?
+        (?:@[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][A-Fa-f0-9]{32,})?
         $
         """, re.VERBOSE)
 

Original file line number	Diff line number	Diff line change
`@@ -209,7 +209,7 @@ def is_valid_docker_image_name(image_name):`
`209`	`209`
`210`	`210`	`(?::([\w][\w.-]{0,127}))? # optional capture <tag-pattern>=':<tag>'`
`211`	`211`	`# optionally capture <digest-pattern>='@<digest>'`
`212`		`- (?:@[A-Za-z][A-Za-z0-9](?:[-_+.][A-Za-z][A-Za-z0-9])*[:][[:xdigit:]]{32,})?`
	`212`	`+ (?:@[A-Za-z][A-Za-z0-9](?:[-_+.][A-Za-z][A-Za-z0-9])*[:][A-Fa-f0-9]{32,})?`
`213`	`213`	`$`
`214`	`214`	`""", re.VERBOSE)`
`215`	`215`