python中判斷變數的型別
python的資料型別有:數字(int)、浮點(float)、字串(str),列表(list)、元組(tuple)、字典(dict)、集合(set)
一般通過以下方法進行判斷:
1、isinstance(引數1,引數2)
描述:該函式用來判斷一個變數(引數1)是否是已知的變數型別(引數2) 類似於type()
引數1:變數
引數2:可以是直接或間接類名、基本型別或者由它們組成的元組。
返回值: 如果物件的型別與引數二的型別(classinfo)相同則返回 True,否則返回 False
例子:
#判斷變數型別的函式
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
# 返回變數型別
def getType(variate):
arr = {"int":"整數","float":"浮點","str":"字串","list":"列表","tuple":"元組","dict":"字典","set":"集合"}
vartype = typeof(variate)
if not (vartype in arr):
return "未知型別"
return arr[vartype]
#判斷變數是否為整數
money=120
print("{0}是{1}".format(money,getType(money)))
#判斷變數是否為字串
money="120"
print("{0}是{1}".format(money,getType(money)))
money=12.3
print("{0}是{1}".format(money,getType(money)))
#判斷變數是否為列表
students=['studentA']
print("{0}是{1}".format(students,getType(students)))
#判斷變數是否為元組
students=('studentA','studentB')
print("{0}是{1}".format(students,getType(students)))
#判斷變數是否為字典
dictory={"key1":"value1","key2":"value2"}
print("{0}是{1}".format(dictory,getType(dictory)))
#判斷變數是否為集合
apple={"apple1","apple2"}
print("{0}是{1}".format(apple,getType(apple)))
返回:
#判斷變數型別的函式
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
# 返回變數型別
def getType(variate):
arr = {"int":"整數","float":"浮點","str":"字串","list":"列表","tuple":"元組","dict":"字典","set":"集合"}
vartype = typeof(variate)
if not (vartype in arr):
return "未知型別"
return arr[vartype]
#判斷變數是否為整數
money=120
print("{0}是{1}".format(money,getType(money)))
#判斷變數是否為字串
money="120"
print("{0}是{1}".format(money,getType(money)))
money=12.3
print("{0}是{1}".format(money,getType(money)))
#判斷變數是否為列表
students=['studentA']
print("{0}是{1}".format(students,getType(students)))
#判斷變數是否為元組
students=('studentA','studentB')
print("{0}是{1}".format(students,getType(students)))
#判斷變數是否為字典
dictory={"key1":"value1","key2":"value2"}
print("{0}是{1}".format(dictory,getType(dictory)))
#判斷變數是否為集合
apple={"apple1","apple2"}
print("{0}是{1}".format(apple,getType(apple)))
返回:
補充:
isinstance() 與 type() 區別:
-
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type() 不會認為子類是一種父類型別,不考慮繼承關係。
-
isinstance() 會認為子類是一種父類型別,考慮繼承關係。
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如果要判斷兩個型別是否相同推薦使用 isinstance()。
2、通過與已知型別的常量進行比