Weekly backup.

20220528110814-string.org

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+:PROPERTIES:
+:ID:       8b686fdd-2abd-459d-8d8d-0c57915de8fb
+:mtime:    20220528112853
+:ctime:    20220528110814
+:END:
+#+title: String
+
+* Méthode /str.translate/
+La méthode /str.translate/ permet d'appliquer une table de substitution à la chaine de caractères :
+#+BEGIN_SRC python :results output
+translation_dict = {ord('a'): ord('A'), ord('b'): "BBB", ord('c'): None}
+print(f'{"aaa bbb ccc".translate(translation_dict) = }')
+#+END_SRC
+#+RESULTS:
+: "aaa bbb ccc".translate(translation_dict) = 'AAA BBBBBBBBB '
+
+* La méthode de classe /str.maketrans/
+La méthode de classe /str.maketrans/ simplifie la création des tables de translation utilisées par /str.stranslate/ en
+supprimant la nécessité d'utiliser la fonction ~ord~ :
+
+#+BEGIN_SRC python :results output
+# Without str.mktrans
+translation_dict = {ord("0"): "1", ord("1"): "0"}
+print(f'{"001011010101001".translate(translation_dict) = }')
+
+# With str.maketrans (single argument)
+translation_dict = str.maketrans({'0': '1', '1': '0'})
+print(f'{"001011010101001".translate(translation_dict) = }')
+
+# With str.maketrans (two arguments)
+translation_dict = str.maketrans("01", "10")
+print(f'{"001011010101001".translate(translation_dict) = }')
+print(f'{"#0F45cd".translate(str.maketrans("abcdef", "ABCDEF")) = }')
+#+END_SRC
+
+#+RESULTS:
+: "001011010101001".translate(translation_dict) = '110100101010110'
+: "001011010101001".translate(translation_dict) = '110100101010110'
+: "001011010101001".translate(translation_dict) = '110100101010110'
+: "#0F45cd".translate(str.maketrans("abcdef", "ABCDEF")) = '#0F45CD'
+
+Le dernier argument de /str.maketrans/ permet de lister les caractères à remplacer par ~None~, à supprimer :
+#+BEGIN_SRC python :results output
+print(f'{"#0F45cd".translate(str.maketrans("abcdef", "ABCDEF", "#")) = }')
+#+END_SRC
+
+#+RESULTS:
+: "#0F45cd".translate(str.maketrans("abcdef", "ABCDEF", "#")) = '0F45CD'
+
+* Références
+ * [[https://mathspp.com/blog/pydonts/string-translate-and-maketrans-methods][String translate and maketrans methods - Pydon't]]
+