Int
Support is converted to type int, only, float
, str
bytes
, and other types are not supported.
float-INT
The decimal point and subsequent values are removed, leaving only the integer part.
STR--INT
If there are characters other than the number (0-9) and the sign (+/-) in the string, an error will be found.
123 |
Int (' 1209 ') # 1209int (' -12 ') # -12int (' +1008 ') # 1008 |
Bytes-INT
If there are characters other than the number (0-9) and the sign (+/-) in the bytes, an error will be found.
123 |
Int (B ' 1209 ') # 1209int (B ' -12 ') # -12int (B ' +1008 ') # 1008 |
Float
Support conversion to float type, only,, int
str
bytes
, and other types are not supported.
float, int
When int is converted to float, a decimal number is automatically added.
1 |
Float (-1209) # -1209.0 |
float, str
If the string contains a positive sign (+/-), a number (0-9), and a decimal point (.) The conversion is not supported for characters other than
12 |
Float (' -1209 ') # -1209.0float (' -0120.29023 ') # -120.29023 |
Bytes-Float
If the bytes contains a sign (+/-), a number (0-9), and a decimal point (.) The conversion is not supported for characters other than
12 |
Float (b ' -1209 ') # -1209.0float (b ' -0120.29023 ') # -120.29023 |
Complex
Only supported int
, float
str
converted to complex types.
Complex int
When int converts complex, the imaginary part is automatically added and 0j
represented.
Float-Complex
When float converts complex, the imaginary part is automatically added and 0j
represented.
1 |
Complex (-12.09) # ( -12.09+0J) |
STR--Complex
When STR converts complex, if it can be converted to int or float, it will convert to complex. A string can also be converted to a complex type value if it conforms exactly to the complex expression rule.
123456789 |
complex ( ' -12.09 ') # ( -12.09+0j) complex ( '-12.0 ') # ( -12+0j), removing the decimal part Complex ( ' -12 ') # ( -12+0j) complex ( ' -12+9j ') # ( -12+9j) complex ( (- 12+9j) ' # ( -12+9j) complex ( ' -12.0-2.0j ') # ( -12-2j), removed the decimal part complex ( ' -12.0-2.09j ') # ( -12-2.09j) complex (b ') # Error, does not support bytes conversion to complex complex (# error, There is no space on either side of the plus sign |
Str
str()
The function can convert any object to a string.
STR, int
The int conversion str will be converted directly and completely.
float-Str
Float converts STR To remove the number of decimal points that are at the bottom of 0.
Complex-Str
Complex convert str, the value is converted to a standard complex expression before being converted to a string.
12 |
STR (Complex ( 9j)) # (12+9j)str (Complex ( 9)) # (12+9j) |
Bytes-Str
The conversion between bytes and Str is a special point, in Python 3.x, strings and bytes are no longer confused, but are completely different data types.
Convert to an executable expression string:
1 |
STR (B ' Hello World ') # b ' Hello World ' |
str()
The function specifies the encoding parameter, or uses the Bytes.decode () method to convert the actual data:
123 |
B ' Hello World '. Decode () # helloWorld str (B ' Hello World ', encoding=' Utf-8 ') # Hello world< /c5>str (B ' \xe4\xb8\xad\xe5\x9b\xbd ', encoding=' Utf-8 ') # China |
List--Str
The value is formatted as a standard list expression before being converted to a string.
123 |
STR ([]) # []str ([1, 2, 3]) # [1, 2, 3]'. Join ([' a ', ' B ', ' C ']) # ABC |
Tuple-Str
The value is formatted as a standard tuple expression before being converted to a string.
123 |
STR (()) # ()str ((1, 2, 3)) # (1, 2, 3)". Join (' a ', ' B ', ' C ') # ABC |
Dict-Str
The value is formatted as a standard dict expression before being converted to a string.
123 |
Str ({' name ': ' hello ', ' age ': + }) # {' name ': ' Hello ', ' age ': +}str ({}) # {} '. Join ({' name ': ' hello ', ' age ': ' ) # nameage |
Set-STR
The value is formatted as a standard set expression before being converted to a string.
123 |
STR (set ({})) # Set ()str ({1, 2, 3}) # {1, 2, 3}'. Join ({' a ', ' B ', ' C '}) # ABC |
Other types
Convert built-in objects:
12 |
STR (int) # <class ' int ';, convert built-in class str (hex) # <built-in function Hex>, convert built-in functions |
To convert a class instance:
123456789 |
class Hello: pass obj = Hello () print (str (obj)) # <__main__. Hello object at 0x1071c6630> |
Conversion functions:
1234567 |
def Hello(): Pass print (str (hello)) # <function Hello at 0x104d5a048> |
bytes
Only str
convert to bytes type is supported.
123 |
' China '. Encode () # b ' \xe4\xb8\xad\xe5\x9b\xbd ' bytes (' China ', encoding=' Utf-8 ') # b ' \xe4\xb8 \XAD\XE5\X9B\XBD ' |
List
Supports conversions to list types, only sequences, such as: STR, tuple, dict, set, and so on.
List by str
1 |
List (' 123abc ') # [' 1 ', ' 2 ', ' 3 ', ' A ', ' B ', ' C '] |
List bytes
Bytes Conversion list, the ASCII decimal value of each byte is taken and combined into a list
1 |
List (B ' Hello ') # [104, 101, 108, 108, 111] |
List by tuple
It is simpler to convert a tuple to a list.
1 |
List ((1, 2, 3)) # [1, 2, 3] |
List Dict
Dictionary conversion list, which takes the key name as the value of the list.
1 |
List ({' name ': ' hello ', ' age ': + }) # [' Name ', ' age '] |
List, set
The collection conversion list, which first goes back to the standard set value, and then transforms.
1 |
List ({1, 2, 3, 3, 2, 1}) # [1, 2, 3] |
Tuple
As with lists, types that are converted to tuple are supported, only sequences.
STR--tuple
1 |
Tuple (' Chinese ') # (' Middle ', ' country ', ' person ') |
Bytes-a tuple
Bytes converts a tuple, taking the ASCII decimal value of each byte and combining it into a list.
1 |
Tuple (B ' Hello ') # (104, 101, 108, 108, 111) |
List-a tuple
1 |
Tuple ([1, 2, 3]) # (1, 2, 3) |
Dict-A tuple
1 |
Tuple ({' name ': ' hello ', ' age ': + }) # (' Name ', ' age ') |
Set-a tuple
1 |
Tuple ({1, 2, 3, 3, 2, 1}) # (1, 2, 3) |
DICTSTR-Dict
List--Dict
Map 2 lists to a dictionary by Zip:
12345 |
List1 = [1, 2, 3, 4]list2 = [1, 2, 3]print (Dict (Zip ( List1, List2)) # {1:1, 2:2, 3:3} |
To convert a nested list to a dictionary:
123456789 |
Li = [[1, 111],[2, 222],[3, 333],] Print (Dict (LI)) # {1:111, 2:222, 3:333} |
Tuple--Dict
Map 2 tuples to a dictionary via zip:
123456 |
TP1 = (1, 2, 3)TP2 = (1, 2, 3, 4) print (dict (Zip (TP1, TP2) ) # {1:1, 2:2, 3:3} |
To convert a nested tuple to a dictionary:
123456789 |
TP = ((1, 111),(2, 222), (3, 333),) print (DICT (TP)) # {1:111, 2:222, 3:333} |
Set--Dict
Map 2 sets to a dictionary by Zip:
123456 |
Set1 = {1, 2, 3}Set2 = {' a ', ' B ', ' C '} print (dict (Zip (Set1, Set2)) # {1: ' C ', 2: ' A ', 3: ' B '} |
SETSTR, set
The characters are first cut into tuples and then converted to collections.
1 |
Print (Set (' Hello ')) # {' L ', ' o ', ' e ', ' H '} |
Bytes, set
The ASCII decimal value of each byte is taken and the Narimoto group is combined and then weighed.
1 |
Set (B ' Hello ') # {104, 108, 101, 111} |
List--Set
First, the list to heavy, and then converted.
1 |
Set ([1, 2, 3, 2, 1]) # {1, 2, 3} |
Tuple--Set
First, the list to heavy, and then converted.
1 |
Set ((1, 2, 3, 2, 1)) # {1, 2, 3} |
Dict, set
The key names of the dictionaries are combined into collections.
123 |
Set ({' name ': ' hello ', ' age ': + }) # {' Age ', ' name '} |
The most complete Python 3 type conversion guide in history