python怎样推断数据类型【Python教程】,python,判断,数据类型

python的数据范例有：数字(int)、浮点(float)、字符串(str)，列表(list)、元组(tuple)、字典(dict)、鸠合(set)。

平常经由过程以下要领举行推断：

1、isinstance(参数1,参数2)

形貌：该函数用来推断一个变量（参数1）是不是是已知的变量范例(参数2) 类似于type()

参数1：变量

参数2：可所以直接或间接类名、基础范例或许由它们构成的元组。

返回值: 假如对象的范例与参数二的范例（classinfo）雷同则返回True，不然返回False。

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例子:

#推断变量范例的函数
def typeof(variate):
    type=None
    if isinstance(variate,int):
       type = "int"
    elif isinstance(variate,str):
      type = "str"
   elif isinstance(variate,float):
     type = "float"
   elif isinstance(variate,list):
       type = "list"
   elif isinstance(variate,tuple):
       type = "tuple"
   elif isinstance(variate,dict):
       type = "dict"
   elif isinstance(variate,set):
       type = "set"
    return type
# 返回变量范例
def getType(variate):
    arr = {"int":"整数","float":"浮点","str":"字符串","list":"列表","tuple":"元组","dict":"字典","set":"鸠合"}
    vartype = typeof(variate)
    if not (vartype in arr):
        return "未知范例"
    return arr[vartype]
    
#推断变量是不是为整数
money=120
print("{0}是{1}".format(money,getType(money)))
#推断变量是不是为字符串
money="120"
print("{0}是{1}".format(money,getType(money)))
money=12.3
print("{0}是{1}".format(money,getType(money)))
#推断变量是不是为列表
students=['studentA']
print("{0}是{1}".format(students,getType(students)))
#推断变量是不是为元组
students=('studentA','studentB')
print("{0}是{1}".format(students,getType(students)))
#推断变量是不是为字典
dictory={"key1":"value1","key2":"value2"}
print("{0}是{1}".format(dictory,getType(dictory)))
#推断变量是不是为鸠合
apple={"apple1","apple2"}
print("{0}是{1}".format(apple,getType(apple)))

2、经由过程与已知范例的常量举行比较

例子：

#推断变量范例的函数
  def typeof(variate):
    type1 = ""
    if type(variate) == type(1):
        type1 = "int"
    elif type(variate) == type("str"):
        type1 = "str"
    elif type(variate) == type(12.3):
        type1 = "float"
    elif type(variate) == type([1]):
        type1 = "list"
    elif type(variate) == type(()):
        type1 = "tuple"
    elif type(variate) == type({"key1":"123"}):
        type1 = "dict"
    elif type(variate) == type({"key1"}):
        type1 = "set"
    return type1
#返回变量范例
  def getType(variate):
    arr = {"int":"整数","float":"浮点","str":"字符串","list":"列表","tuple":"元组","dict":"字典","set":"鸠合"}
    vartype = typeof(variate)
    if not (vartype in arr):
        return "未知范例"
    return arr[vartype]
    
#推断变量是不是为整数
money=120
print("{0}是{1}".format(money,getType(money)))
#推断变量是不是为字符串
money="120"
print("{0}是{1}".format(money,getType(money)))
money=12.3
print("{0}是{1}".format(money,getType(money)))
#推断变量是不是为列表
students=['studentA']
print("{0}是{1}".format(students,getType(students)))
#推断变量是不是为元组
students=('studentA','studentB')
print("{0}是{1}".format(students,getType(students)))
#推断变量是不是为字典
dictory={"key1":"value1","key2":"value2"}
print("{0}是{1}".format(dictory,getType(dictory)))
#推断变量是不是为鸠合
apple={"apple1","apple2"}
print("{0}是{1}".format(apple,getType(apple)))