Python String count() function returns the number of occurrences of a substring in the given string.

Python String count（）函数返回给定字符串中子字符串出现的次数。

Python字符串count（） (Python String count())

The count() function syntax is:

count（）函数的语法为：

str.count(sub[, start[, end]])

sub is the substring to find in the given string.

sub是在给定字符串中找到的子字符串。

start is an optional argument. It specifies the starting index position from where the substring is looked for. Its default value is 0.

start是一个可选参数。 它指定从中查找子字符串的起始索引位置。 默认值为0。

end is an optional argument. It specifies the ending index position in the specified string. Its default value is the length of the string.

end是一个可选参数。 它指定指定字符串中的结束索引位置。 它的默认值是字符串的长度 。

Let’s look at a simple example of string count() function.

让我们看一个简单的字符串count（）函数示例。

s = 'I like Python programming. Python is Awesome!'print(f'Number of occurrence of "Python" in String = {s.count("Python")}')print(f'Number of occurrence of "Python" in String between index 0 to 20 = {s.count("Python", 0, 20)}')

Output:

输出：

Number of occurrence of "Python" in String = 2
Number of occurrence of "Python" in String between index 0 to 20 = 1

Recommended Reading: Python f-strings

推荐读物： Python f字符串

Let’s look at another example where the user will enter the string and substring and we will print the count of occurrences using count() function.

让我们看另一个示例，在该示例中，用户将输入字符串和子字符串，并使用count（）函数打印出现次数。

s = input('Please enter a string:\n')sub = input('Please enter a sub-string:\n')print(f'Number of occurrence of "{sub}" in the "{s}" is {s.count(sub)}')

Output:

输出：

Please enter a string:
a,e,i,o,u
Please enter a sub-string:
,
Number of occurrence of "," in the "a,e,i,o,u" is 4Please enter a string:
Hello World from Python Tutorials from JournalDev
Please enter a sub-string:
from
Number of occurrence of "from" in the "Hello World from Python Tutorials from JournalDev" is 2

Reference: API Doc

参考： API文档

翻译自: https://www.journaldev.com/23754/python-string-count