Python pandas -read_csv是否保持文件打开状态? [英] Python pandas - Does read_csv keep file open?

问题描述

使用pandas read_csv()方法时，它是保持文件打开还是关闭(丢弃文件描述符)?

When using pandas read_csv() method, does it keep the file open or it closes it (discard the file descriptor)?

如果保留，在使用完数据框后如何关闭它?

If it keeps it, how do I close it after I finish using the dataframe?

推荐答案

如果将打开文件传递给它，它将保持打开状态(从当前位置读取)，如果传递字符串，则read_csv将打开和关闭文件.

If you pass it an open file it will keep it open (reading from the current position), if you pass a string then read_csv will open and close the file.

在python中，如果您打开文件却忘记关闭文件，则python会在功能块末尾(在垃圾回收期间)为您关闭文件.

In python if you open a file but forget to close it, python will close it for you at the end of the function block (during garbage collection).

def foo():
    f = open("myfile.csv", "w")
    ...
    f.close()  # isn't actually needed

即如果您调用打开文件的python函数，除非返回文件对象，否则该文件会自动神奇地被自动关闭.

i.e. if you call a python function which opens a file, unless the file object is returned, the file is automagicallymatically closed.

注意:首选语法是with块(在with块的结尾处以及在with块的结尾处关闭f，仅在with块内部定义了f变量):

Note: The preferred syntax is the with block (which, as well as closing f at the end of the with block, defines the f variable only inside the with block):

def foo():
    with open("myfile.csv", "w") as f:
        ...

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