Hi. Yes. You are absolutely right. I'm new to google groups (in fact, this
was my first post). I thought I could edit it after posting it out. Was a
bit in a hurry when writing it down. :O
Also a bit wordy...
On Monday, July 20, 2020 at 8:05:35 PM UTC+8, ajoeiam wrote:
>
> Appreciate very much your informative post. Question below - - -
>
> On Sat, Jul 18, 2020 at 9:14 AM Liu Zheng <firstd...@gmail.com
> <javascript:>> wrote:
>
>> Hi. Doesn't sound like a Django question, but I assume you came across
>> this question when writing Django codes:) So anyway, let me try to see
>> whether I could provide any useful information here.
>>
>> This question is a bit too broad, so let me try to answer it in several
>> levels.
>>
>> First, python doesn't care the format of any file. From python's point of
>> view, any file is just a sequence of binary data. On the lowest level,
>> python only two types of operations: read N bytes from the file starting
>> from a position; write N bytes to the file starting from a position. That's
>> it. What each byte mean is up to the programmers. So on the level of python
>> programming, there's no difference between a txt file and a csv file.
>>
>> Having said the first point, there are standard formats defined by
>> programmers, to make communication easier. First, among all binary files,
>> there's special type of files called "text files". It's special because
>> every byte of a text file must be a value from a certain table of symbols
>> (think of the ASCII table). Not all files are text files. But if a file is
>> a text file, then most text editors can handle that file well. (Python also
>> have native support on the language level, that is, you open a file in the
>> text mode if you use "open(<file name>, 'r')" intead of "open(<file name>,
>> 'rb')". However, this is only for sake of convenience of human readability.
>> It doesn't make a text file fundamentally different from other files. In
>> fact, you can open a text file in the binary mode using 'rb'. Python will
>> simply forget that the file is a text file.
>>
>> Next, text files still form a big family. By assigning meanings to
>> different symbols and creating rules of how the content should look like,
>> there are more types under text files. csv is a special type of text file.
>> (Example of othe types are .py, .html, etc). Since it's just a text file,
>> you can open a csv file using "open(<csv file name>, 'r')" and do
>> read/write operations like any other text file. However, since it has its
>> own rules, there are also some helper libraries to assist you handling csv
>> files, too. Examples are "csv" package, "pandas" package, etc. But again,
>> since it's a text file, you can ignore those packages and write your codes
>> using string functions directly. For example:
>>
>> ```
>> s = open("sample.csv", 'r').read()
>> lines = s.split('\n')
>> first_line = lines[0]
>> columns_lables = first_line.split(',')
>> ......
>> ```
>>
>> Such a piece of codes will handle a very simple and standard csv file
>> already. However, csv has more complications than this. It even has
>> different variations (called dialets).
>>
>
> Did you mean dialects instead of dialets by any chance?
>
>
>> If treating a csv file as an ordinary text file, you are basically
>> re-inventing the wheel. (There's nothing wrong with that. Just tedious.)
>> Those standard packages can handle those staff and let you focus on your
>> business logic. That's all.
>>
>> In the end, I want to emphasize that files' extension names doesn't mean
>> anything. When I said a csv file above, I don't mean a file whose file name
>> ends with ".csv". I mean a file whose content complies the csv rules. By
>> creating a file called "something.csv", I'm merely giving a promise to
>> anyone who open it that "I promise you that the content in this file
>> satisfies the csv rules. You have my words!" Whether I keep my promise or
>> not is totally up to me (indeed, I can rename an image file "pic1.jpg" to
>> "pic1.csv".) In addition, you can save some csv data into a .txt files. For
>> example, consider the following data:
>>
>> Name,Job Title,Phone Number
>> Alice,Manager,23121212
>> Bob,Director,12345678
>> Chales,Developer,41212113
>>
>> You can store the data into "contacts.txt". I will still call it a csv
>> file even though it has ".txt" extension. Therefore, I can handle this file
>> using any csv package. For example:
>>
>> ```
>> import pandas as pd
>> df = pd.read_csv("contacts.txt")
>> ...
>> ```
>>
>> Pandas will not complain just because its extension is not ".csv".
>> However, it will be a good practice to choose the extension which best
>> describes the nature of the file's contents. In this way, you'll bring less
>> confusion to the users of this file (including the future yourself).
>>
>>
>>
>> On Saturday, July 18, 2020 at 2:25:57 PM UTC+8, Sead Sejo Gicić wrote:
>>>
>>> What is the difference between ordinary txt file and csv file for using
>>> in Python programming?
>>>
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>>
>
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