如何在python中一次从文件中读取x个字符？

myfile.txt包含“生存还是毁灭，这是个问题”

我试图编写程序，在换行符上一次输出x个字符，这样x=8的输入将是：

to be or
 not to
be that
is the q
uestion

我不知道如何让我的代码每次继续打印换行符上的下8个字符

def read_file():
    x = int(input("How many letters do you want to read each time : ")) # number of characters to read on each newline
    f = open('myfile.txt')
    contents = f.read(x)
    print(contents) # only prints first 8 characters

read_file()

---

您需要围绕阅读/打印部分进行循环：

def read_file():
    x = int(input("How many letters do you want to read each time : ")) # number of characters to read on each newline
    f = open('myfile.txt')
    while True:
        contents = f.read(x)
        if not contents: 
            break
        print(contents) 

---

您需要通过循环读取它：

contents = []
while True:
  chunk = f.read(x)
  if not chunk:
    break
  contents.append(chunk)

print(contents)

您可以使用“切片”来获取字符串的部分。检查全面的介绍。 我找到的解决办法是：

    def read_file():
        x = int(input("How many letters do you want to read each time : "))
        f = open('myfile.txt')
        contents = f.read()

        temp = x
        temp_string = contents

        while(len(contents) >= temp):
            print(temp_string[:x])
            temp_string = contents[x:]
            contents = temp_string
        print(temp_string[:x])# this need for last part

read_file()

---

请注意，这行代码可以使文件保持打开状态以供读取。尝试使用

with

语句

f = open('myfile.txt')

参考：

其他答案没有错。我想在Python3.8中添加一个带有最近引入的赋值表达式“walrus操作符”的解决方案

参考：

输出：

to be or
 not to 
be that 
is the q
uestion

示例#1

示例2

---

您只需调用

read

一次，因此您当然只会得到前八个字符。您需要多次调用

read

，直到完成。你考虑过某种循环吗？

to be or
 not to 
be that 
is the q
uestion

# -*- coding: utf-8 -*-
def read_n_datas(x_characters,
                 file_path, 
                 my_mode='r', 
                 my_encoding=None):
    with open(file_path, mode=my_mode, encoding=my_encoding) as f:
        assert isinstance(x_characters, int) and x_characters
        r = f.read(x_characters)
        while r:
            y = yield r
            r = f.read(y or x_characters)

x = int(input("How many letters do you want to read each time : ")) # number of characters to read on each newline
e = read_n_datas(x, 'myfile.txt')#read 'x' on first call or as default
next(e)#init the generator
print(e.send(3))#read 3 more characters 
print(e.send(10))#read 10 more characters 
print(e.send(5))#read 5 more characters

x = int(input("How many letters do you want to read each time : ")) # number of characters to read on each newline
e = read_n_datas(x, 'myfile.txt')#read 'x' on first call or as default
for t in e:
    print(t)