table of Contents
Foreword
- print () method for printing out
grammar
print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)
parameter
- objects - complex, it represents a plurality of output objects. A plurality of output objects, need, separated.
- sep - interval for a plurality of objects, the default is a space.
- end - the end of what used to be set. The default is a newline character \ n, we can be replaced with other strings.
- file - the file object to write.
- flush - whether the output is cached usually depends on the file, but if the flush key parameter to True, the flow will be forced to refresh.
Examples
And a digital output string
>>>print("test") # 输出字符串
test
>>> print(100) # 输出数字
100
>>> str = 'test'
>>> print(str) # 输出变量
test
>>> L = [1,2,'a'] # 列表
>>> print(L)
[1, 2, 'a']
>>> t = (1,2,'a') # 元组
>>> print(t)
(1, 2, 'a')
>>> d = {'a':1, 'b':2} # 字典
>>> print(d)
{'a': 1, 'b': 2}
Formatted output integer
>>> str = "the length of (%s) is %d" %('test',len('test'))
>>> print(str)
the length of (test) is 4
>>>
symbol string formatting python
| symbol | description |
|---|---|
| %c | Formatting characters and their ASCII code |
| %s | Format string |
| %d | Integer format |
| in% | Unsigned int format |
| %O | Formatting unsigned octal |
| %x | Unsigned hexadecimal format |
| %X | Unsigned hexadecimal format (uppercase) |
| %f | Format floating point numbers, the point precision may be designated |
| %e | Floating-point format in scientific notation |
| %E | Action with% e, floating point numbers formatted in scientific notation |
| %g | And% f% e shorthand |
| %G | % F% E and shorthand |
| %p | With an address number of variables in hexadecimal format |
Formatting operator assist command
| symbol | Features |
|---|---|
| * | Defined width or point precision |
| - | Used as a left-justified |
| + | Is displayed in front of the positive plus sign (+) |
| <sp> | Show spaces in front of positive numbers |
| # | Display octal number with leading zeros ( '0'), in front of the display hexadecimal '0x' or '0X' (depending on use the 'x' or 'X-') |
| 0 | The figures show the front padding '0' instead of the default space |
| % | '%%' outputs a single '%' |
| (where) | Variable Mapping (dictionary parameter) |
| m.n. | m is the minimum overall width of the display, n is the number of digits after the decimal point (if available) |
Formatted output 16 hex, decimal, octal integer
-
#% X - hex hex
-
#% D - dec Decimal
-
#% O - oct octal
>>>nHex = 0xFF
>>> print("nHex = %x,nDec = %d,nOct = %o" %(nHex,nHex,nHex))
nHex = ff,nDec = 255,nOct = 377
Formatted output float (float)
>>>pi = 3.141592653
>>> print('%10.3f' % pi) #字段宽10，精度3
3.142
>>> print("pi = %.*f" % (3,pi)) #用*从后面的元组中读取字段宽度或精度
pi = 3.142
>>> print('%010.3f' % pi) #用0填充空白
000003.142
>>> print('%-10.3f' % pi) #左对齐
3.142
>>> print('%+f' % pi) #显示正负号
+3.141593
print does not wrap
- In Python print default line break
- To wrap you should not write print (i, end = '')
>>>for i in range(0,3):
... print(i, end = '' )
...
012
Reference: Print function usage summary
