Integer
1. Uses: QQ number, phone number, ID number (without the X's) ...
2. Define the mode: the internal principle equivalent age = 18 # age = int (18)
int only pure digital conversion string, the string will not work with any other, including the decimal point
Hexadecimal conversion
1. Binary Decimal: 10
1*(2**1) + 0*(2**0)
print(int('10',2))
2. octal decimal turn: 110
1*(8**2) + 1*(8**1) + 0*(8**0)
print(int('10',2))
3. Hex turn Decimal: 110
1*(16**2) + 1*(16**1) + 0*(16**0)
print (int ( '110', 16)) 10 rpm decimal radix.
Other binary decimal conversion
Decimal Binary
print (bin (12)) # 0b1100 0b indicates that the following number is a binary number
Decimal to octal
print (oct (12)) # 0o14 0o indicates that the following numbers are octal
Decimal to hexadecimal
print (hex (12)) # 0xc 0x indicates that the following number is a hexadecimal number
And immutable type variable
Variable Type: if the data value is changed, id unchanged
Immutable type: if the data value is changed, id has changed
The int type is immutable
The concept of order and disorder
Use the index value of the data is ordered, or disordered.
So integral are unordered
Float
1. Role: salary, height, weight
2. Definition: internal principle is salary = 1.1 # salar = float (1.1)
String type
1. Role: descriptive data
2. Definitions: internal principle is s = 'hello baby' # s = str ( 'hello baby')
1. Press the index value (value only)
Take forward
s = 'hello world' print(s[0])
Reverse Take
s = 'hello world' print(s[-1])
2. Slice
Care regardless of the end, the step, the interception of a new small strings from a larger string, the left head is fixed, it is fixed to the right end of
S = ' Hello Big Baby ~ ' Print (S [0:. 5]) # Hello Print (S [0: 10:. 1]) # Hello Big step is not written by default. 1 Print (S [0: 10: 2] ) # hlobg step representing a taken every few
Negative values
s = 'hello big baby~' print(s[-1]) print(s[5:0:-1]) print(s[-1:-10:-2])
3. length
len (): statistics is the number of characters in the string (special)
p = ' abcde ' print (referred to as (a))
4. The members of the operation
in and not in: determining whether there is a substring of string in a large
print('egon' in 'egon is dsb and egon is sb') print('g' in 'egon is dsb and egon is sb') print('jason' not in 'egon is dsb and egon is sb')
5. Remove the left and right sides of the character string
strip (): Delete the default left and right sides of the spaces, brackets plus characters, delete the corresponding character
name = ' francis ' print(name.strip()) name1 = '1francis' print(name1.strip('1'))
lstrip (): Only delete the character to the left
name = ' francis ' print(name.lstrip())
rstrip (): Only the right to delete characters
name = ' francis ' print(name.rstrip())
6. Segmentation
split (): for a certain string according to the tissue separator, it can be cut into split list, the value for further
date = ' pick n | 123 | handsome ' print (data.split ( ' | ' ))
rsplit (): from right to left split
= Data ' JASO n-| 123 | Handsome ' Print (data.rsplit ( ' | ', . 1)). 1 # represents the number of the largest divided
Additional: join (): the plurality of types of data elements of the container to be spliced by a specified character string
data = ['1','2','3','a','b'] data1 = '|'.join(data) print(data1)
7. cycle
data = 'jaso n|123| handsome' for i in data: print(i)
8.upper and lower
All uppercase characters
name = 'FranCis' print(name.upper())
All lowercase characters
name = 'FranCis' print(name.lower())
9. in order to determine what the beginning and end characters
= name ' Francis ' Print (name.startswith ( ' F. ' )) # determines whether the string to begin with what Print (name.endswith ( ' S ' )) # determines whether the end of the string to what
Three uses of 10.format
1. The first (by occupying a position consistent with the principles% s)
str1 = 'my name is {} my age is {}'.format('francis',23) str2 = 'my name is {} my age is {}'.format(23,'francis',) print(str1) print(str2)
2. The second (by index placeholder)
str1 = 'my name is {0} my age is {1},{1},{0}'.format('francis',23) print(str1)
3. The third (by name placeholder, the placeholder dictionary of similar key)
str1 = 'my name is {name} my age is {age},{age},{name}'.format(name='francis',age=23) print(str1)
11.replace
A value in the replacement string
= STR ' Francis Age IS 23 is, Francis has A CAR ' RES = str.replace ( ' Francis ' , ' XXX ' ) RES1 = str.replace ( ' Francis ' , ' XXX ' ,. 1) # . 1 represents replacement times, replace the default full- Print (str) Print (RES) Print (res1)
12.isdigit
Determining whether the character string contains all digital
age = '18' age1 = 'aaa' print(age.isdigit()) print(age1.isdigit())
13.find,rfind,index,rindex,count
= S ' Kevin Kevin IS and O IS DSB SB ' Print (s.find ( ' DSB ' )) # returns the index where the d-characters Print (s.find ( ' XXX ' )) # can not find the time no error returns -1 Print (s.find ( ' I ' , 0,4)) # can also be limited by the look index Print (s.index ( ' O ' )) # index character where the return pass value Print (s.index ( ' i ' , 0,3)) # returns the index where the preaching character, will not be found error Print (s.count ( 'the n- ' )) # number of characters appear in statistics
14.center, light, rjust, zfill
= S ' Francis ' Print (s.center (13 is, ' * ' )) # similar centered Print (s.ljust (40, ' ' )) # similar Left Print (s.rjust (40, ' ' )) # is similar to right-align Print (s.zfill (40))
15.expandtabs
Extended tabs
s10 = 'a\tbc' print(s10.expandtabs(100))
16.captalize, swapcase, title
= S12 ' HELLO WORLD sH 20 is ' Print (s12.capitalize ()) # the Hello World initials, does not affect digital Print (s12.swapcase ()) # invert case Print (s12.title ()) # each the first letter of the word capitalized
17.is Digital Series
B = num1 ' . 4 ' # bytes num2 = u ' . 4 ' # Unicode, without adding to python3 u is the Unicode num3 = ' One ' # Chinese digital Num4 = ' IV ' # Roman numerals # '' .isnumeric (): Unicode, Chinese figures, insofar as it represents the Roman numeral numbers are identifying Print (num2.isnumeric ()) Print (num3.isnumeric ()) Print (num4.isnumeric ()) # '' .isdecimal (): Unicode recognizes only ordinary Arabic numerals Print (num2.isdecimal ()) Print (num3.isdecimal ()) Print (num4.isdecimal ()) #'' .isdigit (): bytes, the unicode isdigit usually used has to meet the needs of Print (num1.isdigit ()) Print (num2.isdigit ()) Print (num3.isdigit ()) Print (num4.isdigit ( ))
From the above string is ordered (whenever the index data is ordered), and the type is immutable.
List Type
Role: a plurality of data, multiple accounts, multiple phone numbers, multiple names
Definition: there may be [] values within a plurality of any type, separated by commas, the internal principle is l = [1,3,5,7] # l = list ([1,3,5,7])
1. Press index values (preferably can be kept), sliced
Forward Value
= L [1,2,3,4 ] Print (L [0:. 4: 1]) # 0: represents the range of the representative. 4 step Print (L [0 ::])
Reverse Value
L = [1,2,3,4 ] print (l [5 :: - 1])
Stored value
L = [1,2,3,4 ] l [0] = 69 print (I)
2.append，insert，extend
Add data to the list
l = [11,22,33,44,55] l1 = [99,88,77,66] # 1.尾部添加一个66 l.append(66) # 注意append值能将被添加的数据当作列表的一个元素 print(l) # 2.任意位置添加元素 l.insert(2,96) # 通过索引在任意位置添加元素 print(l) # 注意insert值能将被添加的数据当作列表的一个元素 # 3.添加容器类型数据 l.extend(l1) # 内部原理for循环l1一个个追加到列表的尾部 print(l)
3.len
列表长度，数据个数。
4.in和not in
判断数据是否属于列表
5.删除
del
l = [11,22,33,44,55] print(l) del l[2] # del适用于所有的删除操作，用索引删除 print(l)
remove
l = [11,22,33,44,55] print(l) l.remove(33) # 指定要删除的元素的值 print(l)
6.数据弹出
尾部弹出
l = [11,22,33,44,55] res1 = l.pop() # 尾部弹出 res2 = l.pop() res3 = l.pop() print(res1,res2,res3)
指定位置的数据弹出
l = [11,22,33,44,55] res1 = l.pop(1) # 可以指定索引 按照索引弹出元素 print(res1)
7.循环
l = [11,22,33,44,55] for i in l: print(i)