Python编程必知的12个必备代码片段

# Regular Expression Check Mailimport redef Check_Mail(email): pattern = re.compile(r'([A-Za-z0-9]+[.-_])*[A-Za-z0-9]+@[A-Za-z0-9-]+(.[A-Z|a-z]{2,})+') if re.fullmatch(pattern, email): print("valid") else: print("Invalid")Check_Mail("codedev101@gmail.com") #validCheck_Mail("codedev101-haider@uni.edu")#InvalidCheck_Mail("code-101-work@my.net") # Invalid

# Pro Slicing# list[start:end:step]mylist = [1, 2, 3, 5, 5, 6, 7, 8, 9, 12]mail ="codedev-medium@example.com"print(mylist[4:-3]) # 5 6 7print(mail[8 : 14]) # medium

# Swap without Tempi = 134j = 431[i, j] = [j, i]print(i) #431print(j) #134

# Magic of f-String# Normal Methodname = "Codedev"lang = "Python"data = "{} is writing article on {}".format(name, lang)print(data)# Pro Method with f-stringdata = f"{name} is writing article on {lang}"print(data

# Get Indexx = [10 ,20, 30, 40, 50]print(x.index(10)) # 0print(x.index(30)) # 4print(x.index(50)) # 2

# Sort List based on another Listlist1 =["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m"]list2 = [ 0, 1, 1, 1, 2, 2, 0, 1, 1, 3, 4]C = [x for _, x in sorted(zip(list2, list1), key=lambda pair: pair[0])]print(C) # ['a', 'g', 'b', 'c', 'd', 'h', 'i', 'e', 'f', 'j', 'k']

# Invert the Dictionarydef Invert_Dictionary(data): return{value: key for key, value in data.items()}data = {"A": 1, "B":2, "C": 3}invert = Invert_Dictionary(data)print(invert) # {1: 'A', 2: 'B', 3: 'C'}

# Multi-threadingimport threadingdef func(num): for x in range(num): print(x)if __name__ == "__main__": t1 = threading.Thread(target=func, args=(10,)) t2 = threading.Thread(target=func, args=(20,)) t1.start() t2.start() t1.join() t2.join()

# Element Occur most in Listfrom collections import Countermylst = ["a", "a", "b", "c", "a", "b","b", "c", "d", "a"]# Method 1def occur_most1(mylst): return max(set(mylst), key=mylst.count)print(occur_most1(mylst)) # a# Method 2# Much Faster then Method 1def occur_most2(mylst): data = Counter(mylst) return data.most_common(1)[0][0]print(occur_most2(mylst)) # a

# Split linesdata1 = """Hello toPython"""data2 = """ProgrammingLangauges"""print(data1.split("n")) # ['Hello to', 'Python']print(data2.split("n")) # ['Programming', ' Langauges']

# Map List into Dictionarydef Convert_to_Dict(k, v): return dict(zip(k, v))k = ["a", "b", "c", "d", "e"]v = [1, 2, 3, 4, 5]print(Convert_to_Dict(k, v)) # {'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5}

# Parse Spreadsheetimport csv#Readingwith open("test.csv", "r") as file: csv_reader = csv.reader(file) for row in csv_reader: print(row)file.close()#Writingheader = ["ID", "Languages"]csv_data = [234, "Python", 344, "JavaScript", 567, "Dart"]with open("test2.csv", 'w', newline="") as file: csv_writer = csv.writer(file) csv_writer.writerow(header) csv_writer.writerows(csv_data)