Useful parsing skill with python

In a real coding test, there are many difficulties in conditioning simple string processing. Python can use a variety of built-in functions and regular expressions for string data types as a basic built-in library, so with a few simple taps, you can use them very well.

Extract only the number of digits in a string into dictionary

number_cnt = Counter(re.findall('\d+', string))

Change to All Alphabet Case

# Change to Lowercase
string.lower()

# Change to uppercase
string.upper()

Determine if a string consists only of alphabets or numbers

# Determine if it is made up of only alphabets
"abcd".isalpha() # True
"ab2d".isalpha() # False

# Determine if it consists only of numbers
"123".isdigit() # True
"ab123".isdigit() # False

# Determine if it consists only of alphabets or numbers
"123abc".isalnum() # True
"123##ab".isalnum() # False

regular expression examples

See the link below for full information. Only examples from real problems are summarized.

Well-organized documents

import re
from collections import Counter

# Returns if non-alphabet characters are contained in it
string = "12 #abc# 123"
result = re.findall('[^a-zA-Z]+', string)
print(result) # ['12 #', '# 123']

# Returns the number and number that appears in the string in dict form
string = "{{2},{2,1},{2,1,3},{2,1,3,4}}"
result = Counter(re.findall('\d+', string))
print(result) # Counter({'2': 4, '1': 3, '3': 2, '4': 1})

This post is part of Python-Team-Notes for coding test posting that I posted. If you have any questions or mistakes regarding the code, please point it out!