python get date and judge string

# Filename : util.py
# author by  gulf
 
# 引入 datetime 模块
import datetime

#获取昨天日期
def getYesterday(): 
    today=datetime.date.today() 
    oneday=datetime.timedelta(days=1) 
    yesterday=today-oneday  
    return yesterday
 
# 判断字符串是否是数字
def is_number(s):
    try:
        float(s)
        return True
    except ValueError:
        pass
 
    try:
        import unicodedata
        unicodedata.numeric(s)
        return True
    except (TypeError, ValueError):
        pass
 
    return False

print(getYesterday())
print(is_number("1314"))
print(is_number("gulf"))

operation result: