Merged revisions 75337 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r75337 | georg.brandl | 2009-10-11 10:18:44 +0200 (So, 11 Okt 2009) | 1 line
Update morse script, avoid globals, use iterators.
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diff --git a/Demo/scripts/morse.py b/Demo/scripts/morse.py
new file mode 100755
index 0000000..5aacaa1
--- /dev/null
+++ b/Demo/scripts/morse.py
@@ -0,0 +1,128 @@
+#! /usr/bin/env python
+
+# DAH should be three DOTs.
+# Space between DOTs and DAHs should be one DOT.
+# Space between two letters should be one DAH.
+# Space between two words should be DOT DAH DAH.
+
+import sys, math, aifc
+from contextlib import closing
+
+DOT = 30
+DAH = 3 * DOT
+OCTAVE = 2 # 1 == 441 Hz, 2 == 882 Hz, ...
+
+morsetab = {
+ 'A': '.-', 'a': '.-',
+ 'B': '-...', 'b': '-...',
+ 'C': '-.-.', 'c': '-.-.',
+ 'D': '-..', 'd': '-..',
+ 'E': '.', 'e': '.',
+ 'F': '..-.', 'f': '..-.',
+ 'G': '--.', 'g': '--.',
+ 'H': '....', 'h': '....',
+ 'I': '..', 'i': '..',
+ 'J': '.---', 'j': '.---',
+ 'K': '-.-', 'k': '-.-',
+ 'L': '.-..', 'l': '.-..',
+ 'M': '--', 'm': '--',
+ 'N': '-.', 'n': '-.',
+ 'O': '---', 'o': '---',
+ 'P': '.--.', 'p': '.--.',
+ 'Q': '--.-', 'q': '--.-',
+ 'R': '.-.', 'r': '.-.',
+ 'S': '...', 's': '...',
+ 'T': '-', 't': '-',
+ 'U': '..-', 'u': '..-',
+ 'V': '...-', 'v': '...-',
+ 'W': '.--', 'w': '.--',
+ 'X': '-..-', 'x': '-..-',
+ 'Y': '-.--', 'y': '-.--',
+ 'Z': '--..', 'z': '--..',
+ '0': '-----', ',': '--..--',
+ '1': '.----', '.': '.-.-.-',
+ '2': '..---', '?': '..--..',
+ '3': '...--', ';': '-.-.-.',
+ '4': '....-', ':': '---...',
+ '5': '.....', "'": '.----.',
+ '6': '-....', '-': '-....-',
+ '7': '--...', '/': '-..-.',
+ '8': '---..', '(': '-.--.-',
+ '9': '----.', ')': '-.--.-',
+ ' ': ' ', '_': '..--.-',
+}
+
+nowave = b'\0' * 200
+
+# If we play at 44.1 kHz (which we do), then if we produce one sine
+# wave in 100 samples, we get a tone of 441 Hz. If we produce two
+# sine waves in these 100 samples, we get a tone of 882 Hz. 882 Hz
+# appears to be a nice one for playing morse code.
+def mkwave(octave):
+ sinewave = bytearray()
+ for i in range(100):
+ val = int(math.sin(math.pi * i * octave / 50.0) * 30000)
+ sinewave.extend([(val >> 8) & 255, val & 255])
+ return bytes(sinewave)
+
+defaultwave = mkwave(OCTAVE)
+
+def main():
+ import getopt
+ try:
+ opts, args = getopt.getopt(sys.argv[1:], 'o:p:')
+ except getopt.error:
+ sys.stderr.write('Usage ' + sys.argv[0] +
+ ' [ -o outfile ] [ -p octave ] [ words ] ...\n')
+ sys.exit(1)
+ wave = defaultwave
+ outfile = 'morse.aifc'
+ for o, a in opts:
+ if o == '-o':
+ outfile = a
+ if o == '-p':
+ wave = mkwave(int(a))
+ with closing(aifc.open(outfile, 'w')) as fp:
+ fp.setframerate(44100)
+ fp.setsampwidth(2)
+ fp.setnchannels(1)
+ if args:
+ source = [' '.join(args)]
+ else:
+ source = iter(sys.stdin.readline, '')
+ for line in source:
+ mline = morse(line)
+ play(mline, fp, wave)
+
+# Convert a string to morse code with \001 between the characters in
+# the string.
+def morse(line):
+ res = ''
+ for c in line:
+ try:
+ res += morsetab[c] + '\001'
+ except KeyError:
+ pass
+ return res
+
+# Play a line of morse code.
+def play(line, fp, wave):
+ for c in line:
+ if c == '.':
+ sine(fp, DOT, wave)
+ elif c == '-':
+ sine(fp, DAH, wave)
+ else: # space
+ pause(fp, DAH + DOT)
+ pause(fp, DOT)
+
+def sine(fp, length, wave):
+ for i in range(length):
+ fp.writeframesraw(wave)
+
+def pause(fp, length):
+ for i in range(length):
+ fp.writeframesraw(nowave)
+
+if __name__ == '__main__':
+ main()