day9-Review Learning Python examples

Learning Instance Code

#求1到100的和
Print ("################# #1到100求和 #################")
def sum (A, B):
s = 0
For I in Range (a,b+1):

s = s+i
return s
if __name__ = = ' __main__ ':

sum1 = SUM (0,100)
Print (SUM1)

Print (' ####################### #求1-500 all odd and ########################### ')
Def sumAn (A, B):
m = 0
For I in Range (a,b+1):
If i%2==0:

m = m + I
Continue
Else
Continue


return m
if __name__ = = ' __main__ ':
A= SumAn (1,500)
Print (a)
Print (' ################ #求1 +2!+3!... 20! and ################ ')

Def SUMFAC (A, B):
sum2 = 0
K = 1
For I in Range (a,b+1):
#print (I**i)
K = K*i
sum2 = sum2 + K
Return sum2
if __name__ = = ' __main__ ':
FAC = SUMFAC (1,20)
Print (FAC)

Print (' ###################### #列表排序 ################### ')

def sort (a):
b = Sorted (a)
Return b
if __name__ = = ' __main__ ':
List1 = [2,32,43,453,54,6,576,5,7,6,8,78,7,89]
List1_sort = sort (list1)
Print (List1_sort)

Numeric, String, list. Yuan Zu, dictionary.

Numeric types are divided into types

Integer (int) long integer (long) floating-point (float) complex (complex) a=12j value followed by J

Type () View variable types

String type

There are three ways of defining

’’

“”

‘’’’’’’

Sanchong quotation marks (docstring) can also be used as annotations in addition to defining strings.

Str= ' abc '

Index (starting at 0, 1 = last character, + string connector), slice

Str[0] =a Str[0:2] (2 means take to the first) Str[0::2] means that the two take bits

Str[0:3:-1] represents right-to-left.

strings, lists, and tuples are sequences.

Features: indexing and slicing operations

Basic operation of the sequence

Len (): Find the length of the sequence

+: Connect 2 sequences

*: Repeating sequence elements

In: Whether the discharge element is in the order

Max (): Returns the maximum value

MIN (): Returns the minimum value

CMP (x, y): Compares the sequence of columns for equality

list []

The > list is a data structure that processes an ordered set of items, which can store a sequence of items in a list.

> variable element structure

Create a list

List1=[]

List2=list ()

List3=[' A ',

List2.append () Adding elements to the list

List operations

Take value

Slices and indexes

Add to

List2.append ()

Delete

Del listp[]

List.remove (list[])

Modify

List[]=x

Find

var int list

Insert

List2.insert (1, ' abc ')

Sort

List2.sort ()

Reverse

List2.reverse ()

Delete and return a value

List.pop (1)

Append element

List2.extend (' Qweq ')

Tuple ()

Tuples and lists are similar

Tuples and strings are not becoming

-tuples can store a range of values

-tuples are typically used in user-defined functions to safely take a set of worthwhile times, that is, the value of the tuple being used does not change.

T= (1,a,)

Split of a B c=t tuple

Common methods of dictionaries

> Dictionary is the only type of mapping (hash table) in Python

The > Dictionary object is mutable, but the dictionary must be built using immutable objects, and a dictionary can use different types of key values.

Method of the Dictionary:

Key () value

VALUES () Element

Items () return list

Dic.get () returns the dictionary element.

Dic.has_key (2) Determine if key is in the dictionary

Dic.copy () copy dic2=dic.copy () paste

Dic.clear Clear Elements

Dic.pop (' a ') deletes the K value and returns the element.

Dict () turn a list into a dictionary

Dic.fromkeys (' abc ', 100) Create the same dictionary as the element

day9-Review Learning Python examples