python string, collection

String introduction

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1. Storage of strings in memory;

2. String addition;

3. Formatting of strings;

In [1]: a = 100 

In [2]: a
Out[ 2]: 100 #100<255, occupies one byte in heap memory, one byte is 8 bits, and the maximum value that can be stored is 255.

In [3]: b = "100"

In [4]: b
Out[ 4]: ' 100 ' #corresponds to ASCII code storage, one byte stores any one character, so the string 100 corresponds to 3 characters and occupies 3 bytes. Strings take up a lot of space.

In [5]: type(a)
Out[5]: int

In [6]: type(b)
Out[6]: str

In [4]: b =  '100'
In [7]: c = "200"
In [8]: b + c
Out[8]: '100200'