Python – 用 K 替换给定字符串中的所有数字

给定一个包含数字的字符串，将每个数字替换为 K。

Input : test_str = ‘G4G is 4 all No. 1 Geeks’, K = ‘#’
Output : G#G is # all No. # Geeks
Explanation : All numbers replaced by K.

Input : test_str = ‘G4G is 4 all No. Geeks’, K = ‘#’
Output : G#G is # all No. Geeks
Explanation : All numbers replaced by K.

方法 #1：使用 replace() + isdigit()

在此，我们使用 isdigit() 检查数字，replace() 用于执行将数字替换为 K 的任务。

Python3

# Python3 code to demonstrate working of 
# Replace numbers by K in String
# Using replace() + isdigit()
  
# initializing string
test_str = 'G4G is 4 all No. 1 Geeks'
  
# printing original string
print("The original string is : " + str(test_str))
  
# initializing K 
K = '@'
  
# loop for all characters
for ele in test_str:
    if ele.isdigit():
        test_str = test_str.replace(ele, K)
          
# printing result 
print("The resultant string : " + str(test_str))

输出

The original string is : G4G is 4 all No. 1 Geeks
The resultant string : G@G is @ all No. @ Geeks

方法 #2：使用 regex() + sub()

在此，适当的正则表达式用于识别数字，而 sub() 用于执行替换。

Python3

# Python3 code to demonstrate working of 
# Replace numbers by K in String
# Using regex() + sub()
import re
  
# initializing string
test_str = 'G4G is 4 all No. 1 Geeks'
  
# printing original string
print("The original string is : " + str(test_str))
  
# initializing K 
K = '@'
  
# using regex expression to solve problem 
res = re.sub(r'\d', K, test_str)
          
# printing result 
print("The resultant string : " + str(res)) 

输出

The original string is : G4G is 4 all No. 1 Geeks
The resultant string : G@G is @ all No. @ Geeks