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python sequence, dictionary study notes

高洛峰
高洛峰Original
2017-03-21 13:54:40923browse

First acquaintancepythonMemo:

## Sequence: list, String, Tuplelen(d),d[id],del d[id],data in d

Function:cmp(x,y ),
len(seq),

list(seq) Create a list based on a string,max(args),
min(args),
reversed( seq),
sorted(seq),
tuple(seq)
List method:
append()Add objects at the end,

count()Object count,extend() adds the list at the end,
index() the position of the first matching object,
insert() inserts the object, pop() removes the object,
defaults to the end, remove() moves Except for the first matching object,
reverse() stores it in reverse order,
sort() does not return the list sorting,
sorted() returns the sorted list but the list remains unchanged

element Group: Tuple cannot be modified

The tuple() parameter is a sequence or tuple and returns a tuple

String: Strings are all immutable

find() method, search string, no Return -1, there is a cursor returned
join() method, add elements, return the string of the added element
lower() method, return the lowercase version of the string
replace() method, return matching characters String after string replacement
split() method, string is divided into sequences, inverse method of join


##Dictionary: len(d),d[id],del d[id],data in dMethod:

copy
() Copy the content. If you copy it directly (a=b), it is actually the address. Copy, pointing to the same address fromkey
s([],[]) to initialize the dictionary using the specified key value. Parameter 1 is the sequence of key values. Parameter 2 is the initialized value. The default is noneget(key) method to access the dictionary. No error will be reported if there are no required members. has_key() is equivalent to key in d
items() and returns all dictionaries as a list
keys( ) Return all keys in a list
pop() Remove the key-value corresponding to the key value
popitem() Return a random item to remove
setdefault(key,data) has the same get (), no random key value can be set
z.update(y) uses one dictionary to update another dictionary, and uses y to update z
values() returns the values ​​in the dictionary in the form of a list

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