python
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python [2020/01/03 14:48] admin |
python [2021/05/06 11:15] (current) admin |
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| - | ### Format | + | ## Data Type |
| + | |||
| + | ^ Example ^ Data Type ^ | ||
| + | | x = "Hello World" | str | | ||
| + | | x = 20 | int | | ||
| + | | x = 20.5 | float | | ||
| + | | x = 1j | complex | | ||
| + | | x = ["apple", "banana", "cherry"] | list | | ||
| + | | x = ("apple", "banana", "cherry") | tuple | | ||
| + | | x = range(6) | range | | ||
| + | | x = {"name" : "John", "age" : 36} | dict | | ||
| + | | x = {"apple", "banana", "cherry"} | set | | ||
| + | | x = frozenset({"apple", "banana", "cherry"}) | frozenset | | ||
| + | | x = True | bool | | ||
| + | | x = b"Hello" | bytes | | ||
| + | | x = bytearray(5) | bytearray | | ||
| + | | x = memoryview(bytes(5)) | | | ||
| + | |||
| + | ref: https://medium.com/@shawnren527/learn-about-python-3-data-types-numbers-and-strings-76c75a917c9b | ||
| + | |||
| + | ### Class | ||
| + | ref:https://www.w3schools.com/python/python_classes.asp | ||
| + | |||
| + | ## Create a list of objects from a class | ||
| + | ```python | ||
| + | swatchList = [] | ||
| + | swatchList.append(Swatch("Sky1",22,40,76)) | ||
| + | # Swatch is the name of the class | ||
| + | ``` | ||
| + | <wrap lo> | ||
| + | Reference:\\ | ||
| + | - [[https://www.daniweb.com/programming/software-development/code/216631/a-list-of-class-objects-python|A List of Class Objects]] | ||
| + | </wrap> | ||
| + | |||
| + | ## Format Variables | ||
| ```python | ```python | ||
| print('%s %.2f' % ("hue =",swSky1.hue)) | print('%s %.2f' % ("hue =",swSky1.hue)) | ||
| print('{0} {1:.2f}'.format("hue =",swSky1.hue)) | print('{0} {1:.2f}'.format("hue =",swSky1.hue)) | ||
| print("hue =", format(swSky1.hue,'.2f')) | print("hue =", format(swSky1.hue,'.2f')) | ||
| + | # f:float, x:hex, s:string | ||
| ``` | ``` | ||
| The three lines above give the same result ````hue = 220.00````.\\ | The three lines above give the same result ````hue = 220.00````.\\ | ||
| Line 14: | Line 49: | ||
| - | ### Plot (matplotlib) | + | ## Plot (matplotlib) |
| py37-matplotlib has the following notes:\\ | py37-matplotlib has the following notes:\\ | ||
| The default backend is the interactive Mac OS X backend. Different backends can be specified using the | The default backend is the interactive Mac OS X backend. Different backends can be specified using the | ||
| Line 20: | Line 55: | ||
| https://matplotlib.org/tutorials/introductory/usage.html#backends | https://matplotlib.org/tutorials/introductory/usage.html#backends | ||
| + | ```python | ||
| + | import matplotlib.pyplot as plt | ||
| + | plt.plot(x, y, color='black', linestyle = 'none', marker='o', markerfacecolor=(swatch.r/255.0,swatch.g/255.0,swatch.b/255.0), markersize=12) | ||
| + | ``` | ||
| + | |||
| + | Note: ```markerfacecolor``` accept RGB, HEX and simple color text description: ```markerfacecolor=(r,g,b)```, ```markerfacecolor='#333399'```, ``` markerfacecolor='green'``` | ||
| + | |||
| + | ### 3D plot: | ||
| + | https://jakevdp.github.io/PythonDataScienceHandbook/04.12-three-dimensional-plotting.html | ||
| - | ### Common Error | + | ## Common Error |
| ```python | ```python | ||
| File "main.py", line 15 | File "main.py", line 15 | ||
python.1578034117.txt.gz · Last modified: 2020/01/03 14:48 by admin