Differences in Chinese character calculations: the difference between the lenb function and the len function

The difference between the lenb function and the len function in calculating Chinese characters requires specific code examples

In programming, functions for calculating the length of strings are often used. For English characters, generally use the len function. However, for Chinese characters, sometimes you need to use the lenb function to calculate the string length, because a Chinese character occupies more than one byte in memory.

So, what is the difference between the lenb function and the len function in calculating Chinese characters? The following will be explained through specific code examples.

First, let’s take a look at the usage of the len function. The len function returns the number of characters in the string, whether it is English characters or Chinese characters. Let’s look at an example:

s1 = "Hello World"
s2 = "你好，世界"

print(len(s1))  # 输出 11
print(len(s2))  # 输出 6

In the above example, the string s1 contains 11 characters, including English characters and spaces; the string s2 contains 6 characters, including Chinese characters and punctuation symbol.

Next, let’s take a look at the usage of the lenb function. The lenb function returns the number of bytes in the string, and it can correctly calculate the number of bytes occupied by Chinese characters in memory. Let’s look at an example:

def lenb(string):
    """
    计算字符串的字节数
    """
    return len(string.encode('utf-8'))

s1 = "Hello World"
s2 = "你好，世界"

print(lenb(s1))  # 输出 11
print(lenb(s2))  # 输出 15

In the above example, the string s1 contains 11 bytes, and each English character and space occupies one byte; the string s2 contains 15 bytes , where each Chinese character and punctuation mark takes up 3 bytes.

It can be seen that the result obtained by calculating the number of bytes of Chinese characters through the lenb function is more accurate.

However, it should be noted that the lenb function can only correctly calculate the number of bytes of Chinese characters when the string is encoded as utf-8. If the string is not encoded in UTF-8, you may get incorrect results.

Finally, it needs to be emphasized that in actual programming, when we use functions related to string length, we need to choose the appropriate function according to specific needs. If you only need to count the number of characters in a string, then use the len function; if you need to calculate the number of bytes occupied by Chinese characters in memory, then use the lenb function to be more accurate.

To summarize, the difference between the lenb function and the len function in calculating Chinese characters is mainly reflected in the calculation of the number of bytes occupied by Chinese characters. The len function returns the number of characters in the string, whether it is English characters or Chinese characters; and the lenb function returns the number of bytes in the string, which can correctly calculate the number of bytes occupied by Chinese characters in the memory. Through specific code examples, we can understand their differences and application scenarios more clearly.

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