{"id":38218,"date":"2016-10-24T00:49:41","date_gmt":"2016-10-24T05:49:41","guid":{"rendered":"http:\/\/1004project.tumblr.com\/post\/152237421063"},"modified":"2016-10-24T00:49:41","modified_gmt":"2016-10-24T05:49:41","slug":"mutar-una-lista","status":"publish","type":"post","link":"https:\/\/kenscourses.com\/tc101fall2016\/syndicated\/mutar-una-lista\/","title":{"rendered":"Mutar una lista."},"content":{"rendered":"

--Originally published at Python.<\/a><\/a><\/em>
<\/p>\n

Dijimos antes que las listas son secuencias mutables. Para lograr la mutabilidad Python provee operaciones que nos permiten cambiarle valores, agregarle valores y quitarle valores.Para cambiar una componente de una lista, se selecciona la componente mediante su \u00edndice y se le asigna el nuevo valor:<\/p>

>>> xs[1]=79211>>> xs[78455, 79211, 66540, 45750]<\/p>

Para agregar un nuevo valor al final de la lista se utiliza la operaci\u00f3n append(). Escribi-mosxs.append(47890)para agregar el padr\u00f3n 47890 al final dexs`.<\/p>

>>> xs.append(47890)>>> xs[78455, 79211, 66540, 45750, 47890]>>><\/p>

Para insertar un nuevo valor en la posici\u00f3n cuyo \u00edndice es k (y desplazar un lugar el resto de la lista) se utiliza la operaci\u00f3n insert().Escribimos xs.insert(2, 54988) para insertar el padr\u00f3n 54988 en la tercera posici\u00f3n de xs.<\/p>

>>> xs.insert(2, 54988)>>> xs[78455, 79211, 54988, 66540, 45750, 47890]<\/p>

NotaLas listas no controlan si se insertan elementos repetidos, si necesitamos exigir unicidad, debemos hacerlo mediante el c\u00f3digo de nuestros programas.<\/p>

>>> xs.insert(1,78455)>>> xs[78455, 78455, 79211, 54988, 66540, 45750, 47890]<\/p>

Para eliminar un valor de una lista se utiliza la operaci\u00f3n remove().Escribimos xs.remove(45750) para borrar el padr\u00f3n 45750 de la lista de inscritos:<\/p>

>>> xs.remove(45750)>>> xs[78455, 78455, 79211, 54988, 66540, 47890]<\/p>

Si el valor a borrar est\u00e1 repetido, se borra s\u00f3lo su primera aparici\u00f3n<\/p>

:>>> xs.remove(78455)>>> xs[78455, 79211, 54988, 66540, 47890]<\/p>

AdvertenciaSi el valor a borrar no existe, se produce un error:<\/p>

>>> xs.remove(78)Traceback (most recent call last): \u00a0 File “<stdin>”, line 1, in <module>ValueError: list.remove(x): x not in list<\/p>","protected":false},"excerpt":{"rendered":"

–Originally published at Python. Dijimos antes que las listas son secuencias mutables. Para lograr la mutabilidad Python provee operaciones que nos permiten cambiarle valores, agregarle valores y quitarle valores.Para cambiar una componente de una lista, se selecciona la componente mediante su \u00edndice y se le asigna el nuevo valor:>>> xs[1]=79211>>> xs[78455, 79211, 66540, 45750]Para agregar … Continue reading Mutar una lista.<\/span><\/a><\/p>\n","protected":false},"author":47,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,4],"tags":[],"class_list":["post-38218","post","type-post","status-publish","format-standard","hentry","category-blogs","category-syndicated"],"_links":{"self":[{"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/posts\/38218","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/users\/47"}],"replies":[{"embeddable":true,"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/comments?post=38218"}],"version-history":[{"count":1,"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/posts\/38218\/revisions"}],"predecessor-version":[{"id":38219,"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/posts\/38218\/revisions\/38219"}],"wp:attachment":[{"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/media?parent=38218"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/categories?post=38218"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kenscourses.com\/tc101fall2016\/wp-json\/wp\/v2\/tags?post=38218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}