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This article will explain in detail how to concatenate strings in python. The content of the article is of high quality, so the editor shares it for you as a reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

Plus sign connection

First, in the form of the + sign:

> a, b = 'hello',' world'

> a + b

'hello world' comma connection

Second, through, in the form of commas:

> a, b = 'hello',' world'

> print (a, b)

Hello world

However, one thing to note when using comma form is that it can only be used for print printing, and the assignment operation generates tuples:

> a, b

('hello',' world')

Python's meditation note: in fact, this is not a way of concatenating strings, because 'hello',' world' exists as a tuple, assigning values to variables an and b by unpacking.

Direct connection

Third, you can connect directly with or without spaces:

Print ('hello'' world')

Print ('hello''world')

Python's Zen Note: this is a kind of grammatical candy in Python. Consecutive strings are automatically concatenated into a string. There are no two string objects in memory. (code can slide left and right)

> def x ():

... A = 'aura'

...

> > dis.dis (x)

2 0 LOAD_CONST 1 ('ab')

3 STORE_FAST 0 (a)

6 LOAD_CONST 0 (None)

9 RETURN_ value%

Fourth, use the% operator.

Prior to Python 2.6, the% operator was the only way to format strings, and it could also be used to concatenate strings.

Print ('% s% s'% ('hello',' world')) format function

Fifth, use the format method.

The format method is a string formatting method that appears in Python 2.6 instead of the% operator, and can also be used to concatenate strings.

Print ('{} {} '.format (' hello', 'world') join function

Sixth, use the join built-in method.

A string has a built-in method, join, whose argument is a sequence type, such as an array or tuple.

Print ('- '.join ([' aa', 'bb',' cc'])) f-string

Seventh, use f-string mode.

Python 3.6introduces Formatted String Literals (literal formatted string), which is an evolutionary version of the% operator and the format method for short. The method of concatenating strings using f-string is similar to using the% operator and the format method.

> aa, bb = 'hello',' world'

> f' {aa} {bb}'

'hello world' asterisk *

Eighth, use the * operator.

> aa = 'hello'

> aa * 3

'hello hello hello'

Python's meditation note: the * operator is actually an operator overloading operation, and the corresponding magic method is _ _ mul__

> a = [1]

> axi2

[1, 1]

> a.cake mulberry _ 3

[1,1,1] Summary

The + operator is recommended when concatenating a small number of strings.

If there are high performance requirements and the python version is above 3.6, it is recommended to use f-string. For example, f-string is much better readable than the + sign in the following cases:

A = f 'name: {name} Age: {age} gender: {gender}'

B = 'name:' + name + 'Age:' + age + 'gender:' + gender is here about how to concatenate strings in python. I hope the above content can be helpful to you and learn more. If you think the article is good, you can share it for more people to see.

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