Python

import glob
#获取指定目录下的所有图片
print(glob.glob(r"data/test/*.png"), "\n")#加上r让字符串不转义
#获取上级目录的所有.py文件
print(glob.glob(r'../*.py')) #相对路径

reshape

z = np.array([[1, 2, 3, 4],
          [5, 6, 7, 8],
          [9, 10, 11, 12],
          [13, 14, 15, 16]])
z.shape
(4, 4)

z.reshape(-1)
array([ 1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16])

z.reshape(-1,1)
 array([[ 1],
        [ 2],
        [ 3],
        [ 4],
        [ 5],
        [ 6],
        [ 7],
        [ 8],
        [ 9],
        [10],
        [11],
        [12],
        [13],
        [14],
        [15],
        [16]])
        
z.reshape(-1, 2)
 array([[ 1,  2],
        [ 3,  4],
        [ 5,  6],
        [ 7,  8],
        [ 9, 10],
        [11, 12],
        [13, 14],
        [15, 16]])

模块存放位置

import sys, pprint
    pprint.pprint(sys.path)

查看包内可以从外部调用的方法

import copy

[n for n in dir(copy) if not n.startswith('_')]

字典的创建

girls = ['alice', 'bernice', 'clarice']
letterGirls = {}
for girl in girls:
    letterGirls.setdefault(girl[0], []).append(girl)

D = [1 / 10] * 10
print(D)

[0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1]

import torch
print("hello pytorch {}".format(torch.__version__))
print(torch.cuda.is_available())

hello pytorch 1.7.1+cpu
False # gpu不可用,当输出为True时可用