补充内容.

Signed-off-by: rick.chan <chenyang@autoai.com>

Software/Development/Language/Python/Python_str_与_bytes_之间的转换.md

@@ -1,22 +1,42 @@
-# Python str 与 bytes 之间的转换
+# Python string 与 bytes 之间的转换
+
+总的来说，bytes 和 string 的关系是：
+
+bytes ---decode--> string
+bytes <--encode--- string
+
+常见的几种编码及格式：
+
+* utf8：形如\xe4\xbb\x8a\xe5\xa4
+* unicode：形如\u4eca\u5929\u5929\u6c14\u4e0d\u9519
+
+如果 "\" 变成了 "\\" 说明原字符串是编码后的格式，变成 "\\" 是因为转换成了bytes。
+
+## 1.string 转 bytes
 
 ```python
-# bytes object  
-b = b"example"
-
-# str object  
-s = "example"  
-
-# str to bytes  
-sb = bytes(s, encoding = "utf8")  
-
-# bytes to str  
-bs = str(b, encoding = "utf8")  
-
-# an alternative method  
-# str to bytes  
-sb2 = str.encode(s)  
-
-# bytes to str  
-bs2 = bytes.decode(b)
+s = "abc"           # string
+s = "abc".encode()  # bytes，encode 默认编码方式是 utf-8
+s = b"abc"          # bytes
+# 或
+s = "abc"           # string
+s = bytes(s, encoding = "utf8")     # bytes
+```
+
+## 2.bytes 转 string
+
+```python
+s = b"abc"          # bytes
+s = b"abc".decode() # string，encode 默认编码方式是 utf-8
+s = str(b"")        # string
+# 或
+s = b"abc"          # bytes
+s = str(s, encoding = "utf8")   # string
+```
+
+## 3.bytes 类型的 unicode（中文）输出
+
+```python
+s = '\\u4eca\\u5929\\u5929\\u6c14\\u4e0d\\u9519'    # 中文是：今天天气真不错
+new_s = s.encode().decode('unicode_escape')         # 输出为：今天天气真不错
 ```