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python 正则表达式 匹配指定字符遇到问题记录
匹配1, 12 ,234
错误的例子:
import re
line = "prediction correct 1 >>>>>>>>>>>>>>>>>>>>!real class: 12, predicted class:234 ";
pattern = re.compile(r‘.*real class.*(\d*).*predicted class.*(\d*).*‘)
match_obj = re.search(pattern,line)
print match_obj.groups()
import re
line = "prediction correct 1 >>>>>>>>>>>>>>>>>>>>!real class: 12, predicted class:234 ";
pattern = re.compile(r‘prediction correct.*([0-9]\d*).*real class.*([0-9]\d*).*predicted class.*([0-9]\d*).*‘)
match_obj = re.search(pattern,line)
print match_obj.group()
print match_obj.group(1)
print match_obj.group(2)
正确的结果:
import re
line = "prediction correct 1 >>>>>>>>>>>>>>>>>>>>!real class: 12, predicted class:234 ";
pattern = re.compile(r‘prediction correct.*([0-9]\d*).*real class.*?([0-9]\d*).*predicted class.*?([0-9]\d*).*‘)
match_obj = re.search(pattern,line)
print match_obj.group()
print match_obj.group(1)
print match_obj.group(2)
问题:
1.为什么要加【0-9】
2.注意?的使用,仔细理解
python 正则表达式 匹配指定字符遇到问题记录