I don’t know if it’s the true place to ask, apologizing if not. I started to python one and half week ago. So I’m still beginner.
I made a terminal based weather application with python. What do you think about the code, is it good enough? I mean is it professional enough and how can I make the same functions with more less code?
Here’s the main file (I also added it as url to post): https://raw.githubusercontent.com/TheCitizenOne/openweather/refs/heads/main/openweather.py
Here’s the config.json
file: https://raw.githubusercontent.com/TheCitizenOne/openweather/refs/heads/main/config.json
You appear to be afraid of spaces. Everything is cramped together.
Just bc you don’t have to put a space after colons or after equals and commas and whatnot doesn’t mean you shouldn’t
Don’t be afraid of spaces.
They make it easier for you to read your code when you come back later
Oops, sorry. I will revise the code and place spaces. Thanks for suggestion <3
Usually, you would use a formatter anyway - it’s good to know the standard way but for day to day coding I just have a shortcut bound that runs
ruff format
(you can even have it done automatically on file save).I need to search formatters. Thank you for suggestion.
Ruff
Not the original commenter, but no need to apologise my friend. Nice work. Learning tip from me: give PEP 8 a read and save it for reference somewhere. It’s the standard for how to format Python code, and future you will thank you for internalising it early on in your Python journey
Thank you I will read it.
I revised the code. Added some spaces and comments for better readability. Hope it’s better now.
Instead you should just use an autoformatter. Black is good. Ruff is probably good too but I don’t have a lot of experience with it. YAPF is not good; don’t use it.
It’s mostly ok, my immediate reaction is that it’s unnecessary to put the whole program into a class. Python isn’t Java. It’s fine to write procedures at the top level.
Also as someone said, consider using enums, and also the new case statement as of Python 3.10. Type annotations also can make things clearer. I’ve been using mypy to check mine but there are some alternatives now that might be better.
There is not much error checking but that can be ok if you are the only user.
If the config file might be crafted maliciously, it can use escape codes for a terminal playback attack: https://www.cyberark.com/resources/threat-research-blog/dont-trust-this-title-abusing-terminal-emulators-with-ansi-escape-characters
Be careful of that.
Yes I realized that I put everything to two classes. It’s too much. I’ll make more classes for more attributes.
I didn’t know enums until now and it’s awesome. I will do some exercises about it.
Last thing is interesting. I need to read that. Thank you for suggestions.
There’s no need to make more classes. You can move some of the code so it’s not in any class.
I started to python one and half week ago. So I’m still beginner.
Nice work! Here are a few notes:
The
WeatherApp
object has a mix of attributes with long-term (egself.LOCATIONS
) and short-term (egself.city
) relevance. Instance attributes introduced in places other than__init__
, which makes it non-trivial for a reader to quickly understand what the object contains. And, actually,self.{city,lat,lon}
are all only used from theadd_city
method so they could/should be local variables instead of instance attributes (just remove theself.
from them).There seem to maybe be some bugs around when things are lowercase and when not; for example checking
if self.city.lower() in self.LOCATIONS
but then when writing there the non-lowerself.ctiy
is used as the key toself.LOCATIONS
.The code under
if rep == "1"
andelif rep == "2"
is mostly duplicated, and there is noelse
branch to cover ifrep
is something other than 1 or 2.It looks like the config only persists favorites so far (and not non-favorite cities which the user can add) which isn’t obvious from the user interface.
Passing both
location
andlocations
intoWeatherAPI
so that it can look uplocations[location]
is unnecessary; it would be clearer to pass in the dict for the specific location. It would also be possible to avoid the need forLOWLOCATIONS
by adding a non-lowercasename
key to the per-location dictionaries that just havelat
andlon
right now, and then keepingLOCATIONS
keyed by the lowercase names.HTH! happy hacking :)
That’s very informative, I will rewrite the code with your suggestions. Thank you!
I actually really like doing code reviews, so I’m happy to dig into this one. I have a lot of comments, but please don’t take this as a criticism of your skills, or even of the code itself. I’m just… really thorough ;-) Hopefully, you’ll find some of this helpful.
Formatting
The first suggestion I have is to install a code formatter like ruff or black. The Python community develops our code to a standard called pep8 which you’re violating all over the place here, making it harder to read your code. Rather than having to go through it all and manually conforming it though, tools like
ruff
orblack
will do it with one command. A lot of developers will even plug them into their IDE to run against their code on-save, so you don’t even have to think about running it.CONSTANTS vs attributes
Pep8 says that constants should be in
ALL_CAPS
while attributes should be insnake_case
, and for the most part, it looks like you’re trying to conform to that, but some of your constants aren’t… well constant. You defineself.API_URL
for example as the result of a variable passed to__init__
. This would mean that the value could conceivably be different in two instances of the same class. There’s nothing wrong with that, but labelling it as if it were a constant is bad form.Type Hints
While not necessary for running your program, they’re still super helpful both for readability and ensuring you haven’t introduced any bugs accidentally. If you’re using a proper IDE like PyCharm for example, it will warn you if you’ve passed an int to a method that’s expecting a string for example. As your project gets more complicated, and you start passing around complex objects with varying abilities, type hints can be a big help.
Classes
Don’t listen to the haters on classes. This is great. It’s a good clean way to maintain state inside a component, rather than having to pass objects around to disparate functions.
The Superfluous
else
This is just a pet peeve of mine, but
else
should be used sparingly. There’s nothing wrong with it per se, but it’s often unnecessary. Consider the following two toy examples:def my_func() -> None: if something: return 4 else: return 5
That
else
is useless. the above could be:def my_func() -> None: if something: return 4 return 5
Similarly, this:
def my_func() -> None: if something: x = 1 y = 2 else: raise SomeException(...)
This would be a lot clearer if you invert the test:
def my_func() -> None: if not something: raise SomeException(...) x = 1 y = 2
This comes up all the time, and it just bugs me. I’m not throwing shade, just trying to reduce the number of superfluous else’s in the world :-)
Complex dicts for data
The big offender here is
WeatherApp.LOCATIONS
. You define it first as a constant that you later change (see above), and you reference parts of it all over the place, meaning you’ve got to ensure that every part of your app (a) is familiar with its internals and (b) won’t modify it, thereby breaking other parts of your app accidentally. There’s also thisLOWLOCATIONS
business, which reads like a crutch you added to work around other limitations.Instead, I suggest delegating this sort of thing to a separate class. Consider something like this:
from typing import Self class Location: def __init__(self, name: str, lat: float, lng: float) -> None: self.name = name self.lat = lat self.lng = lng class LocationManager: def __init__(self) -> None: self._locations = [] def add_location(self, name: str, lat: float, lng: float) -> None: self._locations.append(Location(name=name, lat=lat, lng=lng)) @classmethod def build(cls, data: dict[str, dict[str, float]]) -> Self: self = cls() for name, coords in data.items(): self.add_location(name, coords["lat"], coords["lng"]) return self def export(self) -> dict[str, dict[str, float]]: r = {} for loc in self._locations: r[loc.name] = {"lat": loc.lat, "lng": loc.lng} return r
This would offload the complexity carrying around that structure throughout your application and instead define a set API between “how you think about locations” and “how your app uses them”. It’d also let you remove a lot of your location-specific code from the rest of your project where arguably it doesn’t belong.
Defining attritributes in
__init__
It’s fine to change an instance’s attributes from inside a random method, but initialising them should only ever happen in
__init__
. This is largely to do with readability, but also with stability. Consider the following:class Thing: def __init__(self) -> None: pass def do_x(self, something: str) -> None: self.alpha = something def do_y(self) -> None: print(self.alpha) Thing().do_y()
This will barf with an attribute error and when someone looks at the class trying to figure out where
alpha
is set,__init__()
is useless. Now imagine that the class is around 600 lines long and that’s quite the headache.Sometimes, this is rather academic, like where you’ve called
.load_config()
from.__init__()
directly. In these cases, I’d recommend defining the attribute on the class so at least it’s clear that this is something that the class supports externally:class WeatherApp: config: dict[str, str | dict[str, dict[str, float] api_url: str locations: LocationManager def __init__(self, config_file="config.json") -> None: self.load_config(config_file)
Delegation
It’s great that you’re trying to break up your project into responsible parts, but they’re rather tightly coupled, so the responsibility to do anything rests with the entire app rather than any individual part.
For example, you’ve go this
WeatherAPI
class. It’s a good idea. You want to delegate the responsibility of talking to an external API to something that knows how to do that (and only that), but in order to use the one you’ve built here, I’d need to pass it both the name of the city you want to look up, and the entire cities dataset, and the URL it needs to do the job.It’s kind of like asking someone to make you a sandwich, and then taking the time to show them where the bread, ham, and cheese are in the fridge… you might as well make it yourself at that point.
Additionally, your API abstraction isn’t just doing API things, but it’s also handling the rendering step, doing a whole bunch of
print()
and colour formatting etc. That’s not the job of an API.Instead, I suggest building this sort of thing “backwards”. Decide on the API you want, and then build that out. Imagine for a moment how you might want the
WeatherAPI
class to work:class WeatherApp: def __init__(self, ...) -> None ... self.wapi = WeatherAPI(api_url) def run(self) -> None: ... for location in locations: # We can use our `Location` class to pass # everything `.fetch()` needs in one variable. weather = wapi.fetch(location) self.render_daily_weather(weather.current) self.render_current_temperature(weather.temperature)
This drastically simplifies your
WeatherAPI
class and allows you room to add support for things like caching, or handling rate limits etc. Better yet, you can delegate the various bits of data tweaking you’re doing in bothWeatherApp
andWeatherAPI
to a separate class that just accepts raw API data and then distils it down to useful values. In the end, it might look something like this:class WeatherResult: CODES = { 0: "Clear sky", ... } DAY_NIGHT = {0: "Day", 1: "Night"} def __init__(self, current: dict, temperature: float) -> None: self.current = current self.temperature = temperature @property def description(self) -> str: return self.CODES.get( self.current["weather_code"], "Unknown weather code", ) @property def daynight(self) -> str: return self.DAY_NIGHT[self.current["is_day"]] class WeatherAPI: def __init__(self, url: str) -> None: self.url = url def fetch(self, city: Location) -> None: url = f"{self.url}?latitude={city.lat}&longitude" ... return WeatherResult(current=..., temperature=...)
That’s it! Honestly, this is a good start, so please don’t be discouraged by the verbosity of the above. Thanks for sharing your code, and have fun in future projects!
That’s quite a detailed review. Thank you for your attention! I will try everything in here <3
I am pretty new myself, but if you didn’t know, here are some great free resources to help you.
These are looking awesome. Thank you for sharing this <3
No problem at all! I hope it helps :)
Too lazy to check the logic but if possible, consider using enums.
Yes I need to use enums. I realized it now.
Pretty good for a week and a half! I would recommend setting up a project using
uv
and also adding type hints and check them with Pyright (NOT Mypy).