#### Exercise 71 **

Write a **Python algorithm** that takes a **string ‘s’** as input and which determines the **minimum** **digit** within the **string s**. __Example__: if **s = “Python3.7 is more power than Python2.7”** , the algorithm must returns **2**. We assume that the string s does not contain any negative number.

#### Solution

__First method__:

- To solve this exercise we can do it as follow:
- We use the for loop to iterates over every character in the string s.
- We use the isdigit() method to checks if the character is a digit.
- If the character is a digit, we appended it to the digits list as an integer.
- Finally, we use the min method to find the smallest integer in the digits list. In this case, it’s 2.

def min_digit(s): digits = [] for c in s: if c.isdigit(): digits.append(int(c)) return min(digits) s = "Python3.7 is more power than Python2.7" print(min_digit(s)) # Output: 2

__ Second method__: by using the regular expression

import re def min_digit(s): The re.findall('\d', s) method returns a list of all digits in the string s. digits = re.findall('\d', s) # Now we can use the min method() to find the smallest digit in the list return min(digits) s = "Python3.7 is more power than Python2.7" print(min_digit(s)) # Output: 2

**Younes Derfoufi**

**my-courses.net**

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