In Python, format is used to format strings.

In Python, format is used to format strings.
Syntax

It uses {} And: to replace %. "Ing" Example

Pass location

In [1]: '{0},{1}'.format('kzc',18) Out[1]: 'kzc,18'In [2]: '{},{}'.format('kzc',18) Out[2]: 'kzc,18'In [3]: '{1},{0},{1}'.format('kzc',18) Out[3]: '18,kzc,18'

The format function of a string can accept unlimited parameters. The positions can be unordered and not used or used multiple times. However, 2.6 cannot be blank {} or 2.7.

Keyword Parameters

In [5]: '{name},{age}'.format(age=18,name='kzc') Out[5]: 'kzc,18'

Object Attributes

class Person:   def __init__(self,name,age):     self.name,self.age = name,age     def __str__(self):       return 'This guy is {self.name},is {self.age} old'.format(self=self)

In [2]: str(Person('kzc',18)) Out[2]: 'This guy is kzc,is 18 old'

Subscript

In [7]: p=['kzc',18]In [8]: '{0[0]},{0[1]}'.format(p)Out[8]: 'kzc,18

With these convenient "ing" methods, we have the powerful tool of laziness. The basic knowledge of python tells us that list and tuple can be converted into common parameters to the function through "break", while dict can break into keyword parameters to the function (Pass and *). Therefore, you can easily upload a list, tuple, or dict to the format function. Flexible.

Format qualifier

It has a variety of "format delimiters" (The syntax is {} With A: Number), such:

Fill and align

Fill is often used together with alignment

^, <,> Are center, left, right, and back with width

: Enter only one character after the number. If this parameter is not specified, spaces are used by default.

For example

In [15]: '{:>8}'.format('189')Out[15]: '   189'In [16]: '{:0>8}'.format('189')Out[16]: '00000189'In [17]: '{:a>8}'.format('189')Out[17]: 'aaaaa189'

Precision and Type f

Precision is often used with Type f.

In [44]: '{:.2f}'.format(321.33345)Out[44]: '321.33'

Where. 2 indicates the precision of length 2, and f indicates the float type.

Other Types

B, d, o, and x are binary, decimal, octal, and hexadecimal respectively.

In [54]: '{:b}'.format(17)Out[54]: '10001'In [55]: '{:d}'.format(17)Out[55]: '17'In [56]: '{:o}'.format(17)Out[56]: '21'In [57]: '{:x}'.format(17)Out[57]: '11'

The number can also be used as the thousands separator for the amount.

In [47]: '{:,}'.format(1234567890)Out[47]: '1,234,567,890'

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