The methods isdigit(), isnumeric() and isdecimal() are in-built methods of String in python programming language, which are worked with strings as Unicode objects. These functions return either true or false.

方法isdigit() ， isnumeric()和isdecimal()是python编程语言中String的内置方法，可将字符串作为Unicode对象使用。 这些函数返回true或false 。

The comparison is based on Unicode classifications,

比较是基于Unicode分类，

isdecimal()	isdigit()	isnumeric()
Example of string with decimal characters: "12345" "12" "98201"	Example of string with digits: "12345" "1233" "3"	Example of string with numerics: "12345" "½¼" "½" "12345½"
Returns ‘true’ if all characters of the string are decimal.	Returns ‘true’ if all characters of the string are digits.	Returns ‘true if all characters of the string are numeric.
Read more: String isdecimal() Method	Read more: String isdigit() Method	Read more: String isnumeric() Method

isdecimal()	isdigit()	isnumeric()
带十进制字符的字符串示例： “ 12345” “ 12” “ 98201”	带数字的字符串示例： “ 12345” “ 123 3 ” “ 3 ”	带数字的字符串示例： “ 12345” “½¼” “½” “12345½”
如果字符串的所有字符均为十进制，则返回“ true”。	如果字符串的所有字符都是数字，则返回“ true”。	如果字符串的所有字符均为数字，则返回'true。
： 字符串isdecimal()方法	： 字符串isdigit()方法	： 字符串isnumeric()方法

Example:

例：

str1 = u"362436"    #decimal characters
str2 = u"3"         #unicode digit
str3 = u"½¼"        #fractional value
print "str1 :"
print "str1.isdecimal () : ", str1.isdecimal ()
print "str1.isnumeric () : ", str1.isnumeric ()
print "str1.isdigit () : ", str1.isdigit ()
print "str2 :"
print "str2.isdecimal () : ", str2.isdecimal ()
print "str2.isnumeric () : ", str2.isnumeric ()
print "str2.isdigit () : ", str2.isdigit ()
print "str3 :"
print "str3.isdecimal () : ", str3.isdecimal ()
print "str3.isnumeric () : ", str3.isnumeric ()
print "str3.isdigit () : ", str3.isdigit ()

Output

输出量

    str1 :str1.isdecimal () :  Truestr1.isnumeric () :  Truestr1.isdigit () :  Truestr2 :str2.isdecimal () :  Truestr2.isnumeric () :  Truestr2.isdigit () :  Truestr3 :str3.isdecimal () :  Falsestr3.isnumeric () :  Truestr3.isdigit () :  False

翻译自: https://www.includehelp.com/python/difference-between-string-isdecimal-isdigit-isnumeric-and-methods.aspx