要统计一个字符串中汉字的数量，可以使用正则表达式或者遍历字符串的方法。以下是两种方法的示例代码：方法1：使用正则表达式
```python
import re
def count_chinese_characters(text):
pattern = re.compile(r'[\u4e00-\u9fa5]')
chinese_characters = re.findall(pattern, text)
return len(chinese_characters)
text = "Hello 你好 World"
count = count_chinese_characters(text)
print("Number of Chinese characters:", count)
```方法2：遍历字符串
```python
def count_chinese_characters(text):
count = 0
for char in text:
if '\u4e00' <= char <= '\u9fa5':
count += 1
return count
text = "Hello 你好 World"
count = count_chinese_characters(text)
print("Number of Chinese characters:", count)
```这两种方法都可以得到字符串中汉字的数量。希望对你有帮助！