Merge pull request #765 from dastels/master

Twitter API guide code

Author: ladyada

Twitter_API/binascii.py

@@ -0,0 +1,82 @@
+"""
+Copied and tweaked from micropython-lib
+"""
+
+PAD = '='
+
+#pylint:disable=invalid-name,line-too-long
+table_a2b_base64 = b'\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff>\xff\xff\xff?456789:;<=\xff\xff\xff\xff\xff\xff\xff\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\xff\xff\xff\xff\xff\xff\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./0123\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff'
+#pylint:enable=line-too-long
+
+assert len(table_a2b_base64) == 256
+
+def a2b_base64(ascii_data):
+    "Decode a line of base64 data."
+
+    res = []
+    quad_pos = 0
+    leftchar = 0
+    leftbits = 0
+    last_char_was_a_pad = False
+
+    for c in ascii_data:
+        c = chr(c)
+        if c == PAD:
+            if quad_pos > 2 or (quad_pos == 2 and last_char_was_a_pad):
+                break      # stop on 'xxx=' or on 'xx=='
+            last_char_was_a_pad = True
+        else:
+            n = ord(table_a2b_base64[ord(c)])
+            if n == 0xff:
+                continue    # ignore strange characters
+            #
+            # Shift it in on the low end, and see if there's
+            # a byte ready for output.
+            quad_pos = (quad_pos + 1) & 3
+            leftchar = (leftchar << 6) | n
+            leftbits += 6
+            #
+            if leftbits >= 8:
+                leftbits -= 8
+                res.append((leftchar >> leftbits).to_bytes(1, 'big'))
+                leftchar &= ((1 << leftbits) - 1)
+            #
+            last_char_was_a_pad = False
+    else:
+        if leftbits != 0:
+            raise Exception("Incorrect padding")
+
+    return b''.join(res)
+
+# ____________________________________________________________
+
+table_b2a_base64 = (
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/")
+
+def b2a_base64(bin_data):
+    "Base64-code line of data."
+
+    newlength = (len(bin_data) + 2) // 3
+    newlength = newlength * 4 + 1
+    res = []
+
+    leftchar = 0
+    leftbits = 0
+    for c in bin_data:
+        # Shift into our buffer, and output any 6bits ready
+        leftchar = (leftchar << 8) | c
+        leftbits += 8
+        res.append(table_b2a_base64[(leftchar >> (leftbits-6)) & 0x3f])
+        leftbits -= 6
+        if leftbits >= 6:
+            res.append(table_b2a_base64[(leftchar >> (leftbits-6)) & 0x3f])
+            leftbits -= 6
+    #
+    if leftbits == 2:
+        res.append(table_b2a_base64[(leftchar & 3) << 4])
+        res.append(PAD)
+        res.append(PAD)
+    elif leftbits == 4:
+        res.append(table_b2a_base64[(leftchar & 0xf) << 2])
+        res.append(PAD)
+    return ''.join(res).encode('ascii')

Twitter_API/code.py

@@ -0,0 +1,82 @@
+"""
+Halloween countdown for PyPortal.
+
+Adafruit invests time and resources providing this open source code.
+Please support Adafruit and open source hardware by purchasing
+products from Adafruit!
+
+Written by Dave Astels for Adafruit Industries
+Copyright (c) 2019 Adafruit Industries
+Licensed under the MIT license.
+
+All text above must be included in any redistribution.
+"""
+
+#pylint:disable=invalid-name
+import time
+import binascii
+import json
+import board
+from adafruit_pyportal import PyPortal
+import adafruit_esp32spi.adafruit_esp32spi_requests as requests
+
+username = 'codewisdom'
+
+try:
+    from secrets import secrets
+except ImportError:
+    print("""WiFi settings are kept in secrets.py, please add them there!
+the secrets dictionary must contain 'ssid' and 'password' at a minimum""")
+    raise
+
+def halt_and_catch_fire(message, *args):
+    """Log a critical error and stall the system."""
+    print(message % args)
+    while True:
+        pass
+
+def get_bearer_token():
+    """Get the bearer authentication token from twitter."""
+    raw_key = secrets['twitter_api_key'] + ':' + secrets['twitter_secret_key']
+    encoded_key = binascii.b2a_base64(bytes(raw_key, 'utf8'))
+    string_key = bytes.decode(encoded_key)
+    headers = {'Authorization': 'Basic ' + string_key,
+               'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8'}
+    response = requests.post('https://api.twitter.com/oauth2/token',
+                             headers=headers,
+                             data='grant_type=client_credentials')
+    response_dict = json.loads(response.content)
+    if response_dict['token_type'] != 'bearer':
+        halt_and_catch_fire('Wrong token type from twitter: %s', response_dict['token_type'])
+    return response_dict['access_token']
+
+# determine the current working directory
+# needed so we know where to find files
+cwd = ("/"+__file__).rsplit('/', 1)[0]
+url = 'https://api.twitter.com/1.1/statuses/user_timeline.json?count=1&screen_name=' + username
+
+
+# Initialize the pyportal object and let us know what data to fetch and where
+# to display it
+pyportal = PyPortal(url=url,
+                    json_path=(0, 'text'),
+                    status_neopixel=board.NEOPIXEL,
+                    default_bg=cwd + '/twitter_background.bmp',
+                    # external_spi=spi,
+                    # esp=esp,
+                    text_font=cwd+'/fonts/Helvetica-Bold-16.bdf',
+                    text_position=(20, 60),
+                    text_color=0xFFFFFF,
+                    text_wrap=35,
+                    caption_text='@' + username,
+                    caption_font=cwd+'/fonts/Helvetica-Bold-16.bdf',
+                    caption_position=(5, 210),
+                    caption_color=0x808080)
+
+bearer_token = get_bearer_token()
+
+pyportal.set_headers({'Authorization': 'Bearer ' + bearer_token})
+
+while True:
+    pyportal.fetch()
+    time.sleep(3600)       # check every hour