Python String isnumeric()用法及代码示例

Python String isnumeric() 方法是用于字符串处理的 内置 方法。如果字符串中的所有字符都是数字字符，则 issnumeric() 方法返回 “True”，否则返回 “False”。此函数用于检查参数是否包含所有数字字符，如整数、分数、下标、上标、罗马数字等(均以 Unicode 编写)

Syntax: 

string.isnumeric()

参数：

isnumeric() does not take any parameters

返回：

• True - If all characters in the string are numeric characters.
• False - If the string contains 1 or more non-numeric characters.

Errors and Exceptions:

1. It does not contain any arguments, therefore, it returns an error if a parameter is passed.
2. Whitespaces are not considered to be numeric, therefore, it returns “False”
3. Subscript, Superscript, Fractions, Roman numerals (all written in Unicode)are all considered to be numeric, Therefore, it returns “True”

范例1：

Input:string = '1889345'
Output:True

Input:string = '\u00BD'
Output:True

Input:string = '123ayu456'
Output:False

# Python code for implementation of isnumeric()
    
# checking for numeric characters
string = '123ayu456'
print(string.isnumeric())
   
string = '123456'
print( string.isnumeric())

输出：

False
True

范例2：

应用：python中给定一个字符串，计算字符串中数字字符的个数并从字符串中删除，并打印出字符串。

Input:string = '123geeks456for789geeks'
Output:9
         geeksforgeeks

Input:string = '123ayu456'
Output:6
         ayu

算法：

1. 将一个空的 NewString 和变量 count 初始化为 0。
2. 逐个字符遍历给定的字符串直到其长度，检查该字符是否为数字字符。
3. 如果是数字字符，计数器加1，不加到新字符串，否则遍历下一个字符，如果不是数字，继续加到新字符串。
4. 打印计数器的值和 NewString。

# Python implementation to count numeric characters
# in a string and print non numeric characters
# Given string
# Initialising the counter to 0
string ='123geeks456for789geeks'
count = 0
  
newstring1 =""
newstring2 =""
    
# Iterating the string and checking for numeric characters
# Incrementing the counter if a numeric character is found
# And adding the character to new string if not numeric
# Finally printing the count and the newstring
for a in string:
    if (a.isnumeric()) == True:
        count+= 1
    else:
        newstring1+= a
print(count)
print(newstring1)
   
string ='123ayu456'
count = 0
for a in string:
    if (a.isnumeric()) == True:
        count+= 1
    else:
        newstring2+= a
print(count)
print(newstring2)

输出：

9
geeksforgeeks
6
ayu