区分初学者和经验丰富的9种Python编程技能

初学者还是经验丰富？

• 解决问题和提问的艺术
• 了解为什么代码有效（或无效）
• 使用琴弦
• 使用清单
• 使用循环
• 使用函数（和适当的术语）
• 面向对象编程
• 尊重PEP

解决问题和提问的艺术

问题xy

“我需要获取字符串中的最后三个字符。”
“不，不需要！您需要获取文件扩展名。”

def extract_ext(filename):
    return filename[-3:]
print (extract_ext('photo_of_sasquatch.png'))
>>> png

def extract_ext(filename):
    return filename.split('.')[-1]
print (extract_ext('photo_of_sasquatch.png'))
print (extract_ext('photo_of_lochness.jpeg'))
>>> png
>>> jpeg

了解为什么代码有效（或无效）

使用琴弦

word = 'supergreat'
print (f'{word[0]}') 
>>> s
print (f'{word[0:5]}')
>>> super

使用清单

my_list = ['a' , 'b' , 'n' , 'x' , 1 , 2 , 3, 'a' , 'n' , 'b']
for item in my_list:
    print (f'current item: {item}, Type: {type(item)}')

print (my_list.sort())

my_list = ['a' , 'b' , 'n' , 'x' , 1 , 2 , 3 , 'a' , 33.3 , 'n' , 'b']
number_list = []
string_list = []
for item in my_list:
    print (f'current item: {item}, Type: {type(item)}')
    if not isinstance(item,str):
        number_list.append(item)
    else:
        string_list.append(item)
my_list = string_list

my_list = [letter for letter in my_list if isinstance(letter,str)]

def get_numbers(input_char):
    if not isinstance(input_char,str):
        return True
    return False

my_list = [1,2,3,'a','b','c']
check_list = filter(get_numbers, my_list)
for items in check_list:
    print(items)

• 翻转列表（或行）：

names = ['First' , 'Middle' , 'Last']
print(names[::-1])
>>> ['Last', 'Middle', 'First']

• 合并列表项：

names = ['First' , 'Middle' , 'Last']
full_name = ' '.join(names)
print(f'Full Name:\n{full_name}')
>>> First Middle Last

使用循环

greek_gods = ['Zeus' , 'Hera' , 'Poseidon' , 'Apollo' , 'Bob']
for index in range(0,len(greek_gods)):
    print (f'at index {index} , we have : {greek_gods[index]}')

for name in greek_gods:
    print (f'Greek God: {name}')

for index, name in enumerate(greek_gods):
    print (f'at index {index} , we have : {name}')

使用函数（和适当的术语）

def print_list(input_list):
    for each in input_list:
        print(f'{each}')
    print() #just to separate output
greek_gods = ['Zeus' , 'Hera' , 'Poseidon' , 'Apollo' , 'Bob']
grocery_list = ['Apples' , 'Milk' , 'Bread']
print_list(greek_gods)
print_list(grocery_list)
print_list(['a' , 'b' , 'c'])

def reverse_list(list_input):
    return list_input[::-1]
my_list = ['a', 'b' , 'c']
print (reverse_list(my_list))
>>> ['c', 'b', 'a']

面向对象编程

class Student():
    def __init__(self,name):
        self._name = name
        self._subject_list = []

student1 = Student('Martin Aaberge')

student2 = Student('Ninja Henderson')

class Student():
    def __init__(self,name):
        self._name = name
        self._subject_list = []
    def add_subject(self, subject_name):
        self._subject_list.append(subject_name)
    def get_student_data(self):
        print (f'Student: {self._name} is assigned to:')
        for subject in self._subject_list:
            print (f'{subject}')
        print()

#create students:
student1 = Student('Martin Aaberge')
student2 = Student('Heidi Hummelvold')
#add subjects to student1
student1.add_subject('psychology_101')
student1.add_subject('it_security_101')
#add subject to student2
student2.add_subject('leadership_101')
#print current data on students
student1.get_student_data()
student2.get_student_data()

from student import Student
student1 = Student('Martin')
student1.add_subject('biomechanics_2020')
student1.get_student_data()

尊重人

chocolate_cake = 'yummy'

chocolateCake = 'Yummy'

结论