۲۲ ترفند پایتون برای کار با رشته ها — راهنمای کاربردی

1def sub_00(haystack: str="", needle:str="") -> bool:
2    return needle in haystack
3
4assert sub_00("the quick brown fox jumped over the lazy dog", "lazy") == True
5assert sub_00("the quick brown fox jumped over the lazy dog", "lazys") == False

1def string_reverse(forward: str = "") -> str:
2    return forward[::-1]
3
4assert string_reverse("hello") == "olleh"
5assert string_reverse("goodbye") != "goodbye"

1def are_equal(first_comparator: str = "", second_comparator: str = "") -> bool:
2    return first_comparator == second_comparator
3
4
5assert are_equal("thing one", "thing two") is False
6assert are_equal("a thing", "a " + "thing") is True

1def to_uppercase(input_string:str) -> str:
2    return input_string.upper()
3
4def to_lowercase(input_string:str) -> str:
5    return input_string.lower()
6
7def to_sentencecase(input_string:str) -> str:
8    return input_string.capitalize()
9
10def to_titlecase(input_string:str) -> str:
11    return input_string.title()
12
13def to_swapcase(input_string:str) -> str:
14    return input_string.swapcase()
15
16assert to_uppercase("the end of time") == "THE END OF TIME"
17assert to_lowercase("The End Of Time") == "the end of time"
18assert to_sentencecase("The End of Time") == "The end of time"
19assert to_titlecase("the end of time") == "The End Of Time"
20assert to_swapcase("The End Of Time") == "tHE eND oF tIME"

1def concatenate(*argv)->str:
2    return ''.join(argv)
3
4
5assert concatenate("a", "b", "c") == "abc"

1def is_null_or_blank(input_string: str = "") -> bool:
2
3    if input_string: 
4        if input_string.strip():
5            return False
6    return True
7
8
9assert is_null_or_blank(None) == True
10assert is_null_or_blank("") == True
11assert is_null_or_blank("  ") == True
12assert is_null_or_blank(" d ") == False

1def strip_it(input_string: str) -> tuple:
2
3    return (input_string.lstrip(), input_string.rstrip(), input_string.strip())
4
5
6left, right, full = strip_it("  A padded  string   ")
7assert left == "A padded  string   "
8assert right == "  A padded  string"
9assert full == "A padded  string"

1import string
2import secrets
3
4
5def generate_random_string(length: int = 0) -> str:
6    result = "".join(
7        secrets.choice(string.ascii_letters + string.digits)
8        for _ in range(length))
9    return result
10
11
12assert len(generate_random_string(20)) == 20

1def file_to_list(filename: str = "") -> list:
2
3    with open(filename, "r") as f:
4        lines = list(f)
5
6    return lines
7
8
9assert len(file_to_list("<PATH TO FILE>")) == LINE_COUNT

1import nltk
2
3
4def tokenize_text(input_str: str = "") -> list:
5    return nltk.wordpunct_tokenize(input_str)
6
7
8assert tokenize_text("Good muffins cost $3.88\nin New York.") == [
9    "Good",
10    "muffins",
11    "cost",
12    "$",
13    "3",
14    ".",
15    "88",
16    "in",
17    "New",
18    "York",
19    ".",
20]

1import subprocess
2import ast
3
4
5def exec_string(input_string: str = "") -> str:
6    result = subprocess.getoutput(input_string)
7    return result
8
9
10def eval_string(input_string: str = "") -> str:
11    result = ast.literal_eval(input_string)
12    return str(result)
13
14
15assert exec_string("ls -l")
16assert eval_string("{ 'key':'value' }") == "{'key': 'value'}"

1import re
2
3
4def between(first: str = "", second: str = "", input_string="") -> str:
5    
6    m = re.search(f"{first}(.+?){second}", input_string)
7    if m:
8        return m.group(1)
9
10    else:
11        return ""
12
13
14assert between(input_string="adCCCTHETEXTZZZdfhewihu",
15               first="CCC",
16               second="ZZZ") == "THETEXT"

1import string
2
3
4def remove_punctuation(input_string: str = "") -> str:
5    return input_string.translate(str.maketrans("", "", string.punctuation))
6
7
8assert remove_punctuation("Hello!") == "Hello"
9assert remove_punctuation("He. Saw! Me?") == "He Saw Me"

1import urllib.parse
2
3
4def encode_url(url: str = "") -> str:
5    return urllib.parse.quote(url)
6
7
8def decode_url(url: str = "") -> str:
9    return urllib.parse.unquote(url)
10
11
12assert (encode_url("example.com?title=¨ˆπœ˚∑π") ==
13        "example.com%3Ftitle%3D%C2%A8%CB%86%CF%80%C5%93%CB%9A%E2%88%91%CF%80")
14assert decode_url("example.com?title=%a0%f7%b1") == "example.com?title=���"

1import base64
2
3
4def encode_b64(input_string: str = "") -> object:
5    return base64.b64encode(input_string.encode("utf-8"))
6
7
8def decode_b64(input_string: str = "") -> object:
9    return base64.b64decode(input_string).decode("utf-8")
10
11
12assert encode_b64("Hello") == b"SGVsbG8="
13assert decode_b64(b"SGVsbG8=") == "Hello"

1import difflib
2
3
4def similarity(left: str = "", right: str = "") -> float:
5
6    seq = difflib.SequenceMatcher(None, left, right)
7    return seq.ratio()
8
9
10assert similarity("I like bananas", "I like bananarama") >= 0.80
11assert similarity("I like bananas", "The quick brown fox") <= 0.25

1def remove_by_index(original: str = "", index: int = -1) -> tuple:
2    if len(original) >= index and index >= 0:
3        return (original[:index] + original[index + 1:], original[index])
4    else:
5        return (original, "")
6
7
8assert remove_by_index("0123456789", 5) == ("012346789", "5")
9view rawstrings_22_remove_at_index.py hosted with ❤ by GitHub

1def from_csv_line(line: str = "") -> list:
2
3    return line.split(",")
4
5
6assert from_csv_line("a,b,c") == ["a", "b", "c"]

1def from_list(line: list = []) -> str:
2
3    ret = ", ".join(e for e in line)
4    return ret
5
6
7assert from_list(["a", "b", "c"]) == "a, b, c"
8assert from_list(["one", "two", "three"]) == "one, two, three"

1import itertools
2
3
4def interleave(left: str = "", right: str = "") -> str:
5
6    return "".join(
7        [i + j for i, j in itertools.zip_longest(left, right, fillvalue="")])
8
9
10assert interleave("ABCD", "01") == "A0B1CD"

1def remove_unwanted(original: str = "",
2                    unwanted: str = "",
3                    replacement: str = "") -> str:
4                    
5    return original.replace(unwanted, replacement)
6
7
8assert remove_unwanted(original="M'The Real String'",
9                       unwanted="M") == "'The Real String'"

1def find_char_locations(original: str = "", character: str = "") -> list:
2
3    return [index for index, char in enumerate(original) if char == character]
4
5
6assert find_char_locations("The jolly green giant.", "e") == [2, 12, 13]

1def to_leetspeak(normal_speak:str="") -> str:
2
3    leet_mapping = str.maketrans("iseoau", "1530^Ü")
4    return normal_speak.translate(leet_mapping).title().swapcase()
5
6assert to_leetspeak("the quick brown fox jumped over the lazy dogs") == \
7    "tH3 qÜ1cK bR0wN f0x jÜMP3d 0v3r tH3 l^zY d0g5"