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--- python [2024/10/31 19:57] – created - external edit 127.0.0.1
+++ python [2026/04/28 16:34] (current) – [error: externally-managed-environment] donald
@@ Line 1: / Line 1: @@
 ====== Python ======
+===== create window usb install =====
+=== Using WoeUSB-NG (Recommended GUI) ===
+<code>
+sudo apt update
+sudo apt install git p7zip-full python3-pip python3-wxgtk4.0
+sudo pip3 install WoeUSB-ng --break-system-packages
+</code>
+Run woeusb from the application menu
+===== error: externally-managed-environment =====
+<code>
+pip install <package-name> --break-system-packages
+</code>
+===== Testing for odd =====
+<code>
+num = 7
+if num % 2 != 0:
+    print(f"{num} is odd.")
+</code>
+===== Lists =====
+  * Lists are Python's version of arrays.
+  * They are mutable and zero based indexed.
+  * list = ['tom', 'dick', 'harry']
+  * if 'tom' in list returns true
+===== Importing code =====
+  * from //machine import PIN// means get the PIN class from the file machine
+  * from //ir_rx.nec import nec_8// means get the NEC_8 class from the file nec in the directory ir_rx
+===== Range =====
+  * Range is start, stop, step to generate a range of numbers
+<code>
+# print 0 - 4
+for i in range(5):
+    print(i)
+</code>
+===== Passing Variables =====
+  *** Use classes!**
+  * Python will not change what I think are global variables in functions.
+  * If, for example, you have a variable xyzzy, and you reference it in a function, python creates a new one.
+  * So you have to pass in xyzzy if you want to modify it.
+  * You then have to return it explicitly, because Python returns the value of the last expression.
+<code>
+    def incrementXyzzy():
+       xyzzy = xyzzy + 1
+    #does not work because xyzzy is a local created on the fly
+</code>
+<code>
+    def incrementXyzzy(xyzzy):
+       xyzzy = xyzzy + 1
+    #xyzzy is passed in and can be incremented. it will be returned
+</code>
+<code>
+    def incrementXyzzy(xyzzy):
+       xyzzy = xyzzy + 1
+    return xyzzy   #explict return is better
+    #xyzzy is passed in and can be incremented. it will be returned
+</code>
+<code>
+    xyzzy = incrementXyzzy(xyzzy):
+    #the calling function MUST assign the returned value
+</code>
 ===== Read Csv =====
@@ Line 62: / Line 145: @@
 file.close()
 </code>
+==== Packages ====
+  * packages live in C:\Users\Donald\AppData\Local\Programs\Python\Python313\Lib\site-packages
+  * a pip install of exifread appeared to work but did not create this package in the above directory
+  * found it on Git, downloaded a zip, and copied the package to the site-packages directory