Your data is not valid JSON format. You have [] when you should have {} for the “masks” and “parameters” elements: [] are for JSON arrays, which are called list in Python {} are for JSON objects, which are called dict in Python Here’s how your JSON file should look: { “maps”: [ { “id”: … Read more
In Python 3, print can take an optional flush argument: print(“Hello, World!”, flush=True) In Python 2, after calling print, do: import sys sys.stdout.flush() By default, print prints to sys.stdout (see the documentation for more about file objects).
The syntax is the * and **. The names *args and **kwargs are only by convention but there’s no hard requirement to use them. You would use *args when you’re not sure how many arguments might be passed to your function, i.e. it allows you pass an arbitrary number of arguments to your function. For … Read more
The simplest way in Python: import time start_time = time.time() main() print(“— %s seconds —” % (time.time() – start_time)) This assumes that your program takes at least a tenth of second to run. Prints: — 0.764891862869 seconds —
data is a Python dictionary. It needs to be encoded as JSON before writing. Use this for maximum compatibility (Python 2 and 3): import json with open(‘data.json’, ‘w’) as f: json.dump(data, f) On a modern system (i.e. Python 3 and UTF-8 support), you can write a nicer file using: import json with open(‘data.json’, ‘w’, encoding=’utf-8′) … Read more
>>> str(42) ’42’ >>> int(’42’) 42 Links to the documentation: int() str() str(x) converts any object x to a string by calling x.__str__().
This works for everyone: pip install -r /path/to/requirements.txt Explanation: -r, –requirement < filename > Install from the given requirements file. This option can be used multiple times.
When using matplotlib.pyplot.savefig, the file format can be specified by the extension: from matplotlib import pyplot as plt plt.savefig(‘foo.png’) plt.savefig(‘foo.pdf’) That gives a rasterized or vectorized output respectively. In addition, there is sometimes undesirable whitespace around the image, which can be removed with: plt.savefig(‘foo.png’, bbox_inches=”tight”) Note that if showing the plot, plt.show() should follow plt.savefig(); … Read more
From the docs: The SimpleHTTPServer module has been merged into http.server in Python 3.0. The 2to3 tool will automatically adapt imports when converting your sources to 3.0. So, your command is python -m http.server, or depending on your installation, it can be: python3 -m http.server
Using slicing: >>> ‘hello world'[::-1] ‘dlrow olleh’ Slice notation takes the form [start:stop:step]. In this case, we omit the start and stop positions since we want the whole string. We also use step = -1, which means, “repeatedly step from right to left by 1 character”.