Python list與NumPy array 區分詳解
阿新 • • 發佈:2020-01-09
1. 資料型別 type()
#!/usr/bin/env python # -*- coding: utf-8 -*- # Yongqiang Cheng from __future__ import absolute_import from __future__ import print_function from __future__ import division import os import sys sys.path.append(os.path.dirname(os.path.abspath(__file__)) + '/..') current_directory = os.path.dirname(os.path.abspath(__file__)) import numpy as np # import tensorflow as tf import cv2 import time print(16 * "++--") print("current_directory:",current_directory) PIXEL_MEAN = [123.68,116.779,103.939] # R,G,B. In TensorFlow,channel is RGB. In OpenCV,channel is BGR. print("Python list") print("PIXEL_MEAN:",PIXEL_MEAN) print("type(PIXEL_MEAN):",type(PIXEL_MEAN)) print("type(PIXEL_MEAN[0]):",type(PIXEL_MEAN[0]),"\n") PIXEL_MEAN_array = np.array(PIXEL_MEAN) print("NumPy array") print("PIXEL_MEAN_array:",PIXEL_MEAN_array) print("type(PIXEL_MEAN_array):",type(PIXEL_MEAN_array)) print("type(PIXEL_MEAN_array[0]):",type(PIXEL_MEAN_array[0])) print("PIXEL_MEAN_array.dtype:",PIXEL_MEAN_array.dtype)
/usr/bin/python2.7 /home/strong/tensorflow_work/R2CNN_Faster-RCNN_Tensorflow/yongqiang.py --gpu=0 ++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++-- current_directory: /home/strong/tensorflow_work/R2CNN_Faster-RCNN_Tensorflow Python list PIXEL_MEAN: [123.68,103.939] type(PIXEL_MEAN): <type 'list'> type(PIXEL_MEAN[0]): <type 'float'> NumPy array PIXEL_MEAN_array: [123.68 116.779 103.939] type(PIXEL_MEAN_array): <type 'numpy.ndarray'> type(PIXEL_MEAN_array[0]): <type 'numpy.float64'> PIXEL_MEAN_array.dtype: float64 Process finished with exit code 0
2. 資料融合 (data fusion)
#!/usr/bin/env python # -*- coding: utf-8 -*- # Yongqiang Cheng from __future__ import absolute_import from __future__ import print_function from __future__ import division import os import sys sys.path.append(os.path.dirname(os.path.abspath(__file__)) + '/..') current_directory = os.path.dirname(os.path.abspath(__file__)) import numpy as np # import tensorflow as tf import cv2 import time print(16 * "++--") print("current_directory:",PIXEL_MEAN_array.dtype,"\n") image_array = np.array( [[[1,2,3],[4,5,6],[7,8,9],[10,11,12]],[[21,22,23],[24,25,26],[27,28,29],[30,31,32]]]) print("image_array:",image_array) print("type(image_array):",type(image_array)) print("type(image_array[0]):",type(image_array[0])) print("image_array.dtype:",image_array.dtype,"\n") image_array_fusion = image_array + np.array(PIXEL_MEAN) print("image_array_fusion:",image_array_fusion) print("type(image_array_fusion):",type(image_array_fusion)) print("type(image_array_fusion[0]):",type(image_array_fusion[0])) print("image_array_fusion.dtype:",image_array_fusion.dtype)
/usr/bin/python2.7 /home/strong/tensorflow_work/R2CNN_Faster-RCNN_Tensorflow/yongqiang.py --gpu=0 ++--++--++--++--++--++--++--++--++--++--++--++--++--++--++--++-- current_directory: /home/strong/tensorflow_work/R2CNN_Faster-RCNN_Tensorflow Python list PIXEL_MEAN: [123.68,103.939] type(PIXEL_MEAN): <type 'list'> type(PIXEL_MEAN[0]): <type 'float'> NumPy array PIXEL_MEAN_array: [123.68 116.779 103.939] type(PIXEL_MEAN_array): <type 'numpy.ndarray'> type(PIXEL_MEAN_array[0]): <type 'numpy.float64'> PIXEL_MEAN_array.dtype: float64 image_array: [[[ 1 2 3] [ 4 5 6] [ 7 8 9] [10 11 12]] [[21 22 23] [24 25 26] [27 28 29] [30 31 32]]] type(image_array): <type 'numpy.ndarray'> type(image_array[0]): <type 'numpy.ndarray'> image_array.dtype: int64 image_array_fusion: [[[124.68 118.779 106.939] [127.68 121.779 109.939] [130.68 124.779 112.939] [133.68 127.779 115.939]] [[144.68 138.779 126.939] [147.68 141.779 129.939] [150.68 144.779 132.939] [153.68 147.779 135.939]]] type(image_array_fusion): <type 'numpy.ndarray'> type(image_array_fusion[0]): <type 'numpy.ndarray'> image_array_fusion.dtype: float64 Process finished with exit code 0
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