Python Base Point Introduction

Special data types

>>> List1 = [1, ' Wang ', ' tao ']>>> tuple1 = (2, ' Wang ', ' Tao ', ' Yuan ')    #tuple的内容不可更改 >>> dict 1 = {           #dict的元素分为 key:value two parts, key cannot repeat ' Wang ': ' Tao ': ' Yuan ': 100}

The use of dict, transferred from

Operationresultnoteslen (a) the number of items in a dictionary is obtained by a[k]the item of a with key K gets the value corresponding to the key K (1), (ten) a[k] = Vset A [K] to V set key K corresponding value becomes v del a[k]remove A[k] From a removes the element with the key k from the dictionary (1) a.clear () Remove all items from a clears the entire dictionary a.copy () A (shallow Copy of a Gets the dictionary copy k in Atrue if A has a key K, else false exists in the dictionary key K is returned true, no then returns False (2) k not in aequivalent to not K in a The key k does not exist in the dictionary and returns true, whereas the inverse returns False (2) A.has_key (k) equivalent to K in a, the use of the form in new code equivalent to the K in a a.items () a copy of a ' s List of (key, value) pairs gets a key, the value of the list (3) A.keys () a copy of a ' s list of keys gets the list (3) a.update ([b]) updates (and Overwri TES) Key/value pairs from B update a dictionary from the B dictionary, update if the key is the same, append (9) A.fromkeys (seq[, value]) creates a new dictionary with keys from Seq and values set to value (7) a.values () a copy of A's list of values (3) A.get (k[, X]) a[k] If k in a, else X (4) A.setdefaul T (k[, X]) a[k] If k in a, else X (also setting it) (5) A.pop (k[, X]) a[k] If k in a, else X (and remove K) (8) A.popitem () remove and return an arbitrary(key, value) pair (6) A.iteritems () return an iterator-over (key, value) pairs (2), (3) A.iterkeys () return a iterator over the Mapping's keys (2), (3) a.itervalues () return an iterator over the mapping ' s values (2), (3)

Set ([,]) is a list of key dict, with elements that are not repeatable

Special Operations

define function Def f (): F is the function name, note that you want to add a colon later

Add action Append () Append to list tail

Extend () After adding list B to a

Insert (1, ' G ')