Kangrui‘s Python Learning Diary 2020-07-27

学习了关于文件处理以及代码测试的内容
以下所用文件可以在 “图灵社区” 免费下载

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文件处理部分

# 建立相对路径的方法如下：
# file_path = 'C:\Users\other_files\text_files\filename.txt'
# with open(file_path) as file_object
with open('text_file\pi_digits.txt') as file_object:  # 传递绝对路径
    contents = file_object.read()
    print(contents)
    # 文末会有1个空行，因为read()到达文件末尾时返回一个空字符串
    print(contents.rstrip())

# 逐行读取
filename = 'text_file\pi_digits.txt'
with open(filename) as file_object:
    for line in file_object:
        print(line)

with open(filename) as file_object:
    lines = file_object.readlines()  # 读取每一行并存在一个列表中
for line in lines:
    print(line.rstrip())

pi_string = ''
for line in lines:
    pi_string += line.rstrip()

print(pi_string)  # 左边也有空格
print(len(pi_string))

pi_string = ''
for line in lines:
    pi_string += line.strip()

print(pi_string)
print(len(pi_string))

输出结果为：
3.1415926535
8979323846
2643383279

3.1415926535
8979323846
2643383279
3.1415926535

8979323846

2643383279

3.1415926535
8979323846
2643383279
3.1415926535 8979323846 2643383279
36
3.141592653589793238462643383279
32

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检测生日是否在圆周率前百万位
这部分有需要输入的内容，故不展示输出

filename = 'text_file\pi_million_digits.txt'
with open(filename) as file_object:
    lines = file_object.readlines()  # 读取每一行并存在一个列表中

pi_string = ''
for line in lines:
    pi_string += line.strip()

print(pi_string[:52] + "...")
print(len(pi_string))

birthday = input("Enter your birthday, in the form mmddyy:")
if birthday in pi_string:
    print("Your birthday appears in the first million digits of pi!")
else:
    print("Failed.")

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文件写入及读取部分

# 写入空文件
filename = 'programming.txt'
with open(filename,'w') as file_object:
    # 以写入的方式打开文件，若无文件将创建文件
    file_object.write("I love programming.\n")
    file_object.write("I love creating new games.\n")
    # 每次输入都会覆盖原本的内容

# 以追加的方式打开
with open(filename,'a') as file_object:
    file_object.write("I love finding meaning in large database.\n")
    file_object.write("I love creating apps that run in a browser.\n")

# 使用try-except代码块解决异常
try:
    print(5/0)
except ZeroDivisionError:
    print("You can't divide by zero!")
    # 并非真正的解决，而是以不报错的方式继续运行

while True:
    first_num = input("\nFirst number:")
    if first_num == 'q':
        break
    second_num = input("\nSecond number:")
    try:
        answer = int(first_num)/int(second_num)
    except ZeroDivisionError:
        print("You can't divide by zero!")
    else:
        print(answer)

# 失败时一声不吭：使用pass命令

# 使用json模块存储数据
import json

numbers = [2,3,5,7,11,13]
filename = 'number.json'
with open(filename,'w') as f_obj:
    json.dump(numbers,f_obj)

with open(filename) as f_obj:
     new_numbers = json.load(f_obj)

print(new_numbers)

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函数测试部分

def get_formatted_name(first, last, middle=''):
    if middle:
        full_name = first + ' ' + middle + ' ' +last
    else:
        full_name = first + ' ' +last
    return full_name.title()

class NamesCase(unittest.TestCase):
    def test_first_last_name(self):
        formatted_name = get_formatted_name('janis', 'joplin')
        self.assertEqual(formatted_name, 'Janis Joplin')

    def test_first_middle_last_name(self):
        formatted_name = get_formatted_name('janis', 'joplin', 'stupid')
        self.assertEqual(formatted_name, 'Janis Stupid Joplin')

# 各种断言方式
    # assertEqual
    # assertNotEqual
    # assertTrue:判断是否为真
    # assertFalse
    # assertIn:判断是否在列表中
    # assertNotIn

# 方法setup()
    # 用以创建一个调查对象，一个答案列表