文件操作

1.with打开

with open(r'E:\py\text_files\pi.txt') as file_object:  # 在冒号前加r表示以原始字符串方式指定路径，否则会出现\t的转义符报错或者用\\表示路径
    contents = file_object.read()
    print(contents.strip())

2.逐行读取及打印

filename = 'E:\py\\text_files\pi.txt'
with open(filename) as file_object:  # 在冒号前加r表示以原始字符串方式指定路径，否则会出现\t的转义符报错或者用\\表示路径
    contents = file_object.readlines()  # 逐行读取
    for i in contents:
        print(i.strip())  # 逐行打印，去除空行的空格

3.调整指针

filename = r'E:\py\text_files\pi.txt'
with open(filename) as file_object:  # 在冒号前加r表示以原始字符串方式指定路径，否则会出现\t的转义符报错或者用\\表示路径
    contents = file_object.readlines()  # 逐行读取
    # file_object.seek(20)#调整指针位置
    print(file_object.tell())  # 42获取指针位置
a = ''
for i in contents:
    a = a + i.strip()  # 拼接字符串
print(a)  # 3.141592653589793238462643383279
print(len(a))  # 32

 4.替换字符

with open(r'e:\py\text_files\pi.txt', 'r', encoding='utf-8')  as abc:
    for i in abc.readlines():
        c = i.replace('Python', 'C++')
        print(c.strip())
'''In C++ you can create class
In C++ you can use loops
In C++ you can look at function'''