python学习随笔

路径相关

#导入os
import os
#获取当前路径
os.getcwd()
#在当前新建文件夹
path = os.getcwd()+\"\\\\新建文件夹\"
os.makedirs(path)
#拼合路径
file_name = \"新建文件夹\"
path = os.path.join(\".\", file_name)

一段简单创建文件的程序

一种写法

import os
file_name = \"新建文件夹\"
def creat_cur_file(file_name):
	path = os.path.join(\".\", file_name)
	isExist = os.path.exists(path)
	if not isExist:
		os.makedirs(path)
		return True
	else:
		print(path+\" 目录已存在\")
		return False
creat_cur_file(file_name)

从指定网址下载数据

一种写法

import os 
import tarfile
from six.moves import urllib
DOWNLOAD_ROOT = \"https://raw.githubusercontent.com/ageron/handson-ml/master/\"
HOUSING_URL = DOWNLOAD_ROOT + HOUSING_PATH + \"/housing.tgz\"

def fetch_housing_data(housing_url=HOUSING_URL, housing_path=HOUSING_PATH):
	if not os.path.isdir(housing_path):
		os.makedirs(housing_url)
	tgz_path = os.path.join(housing_path, \"housing.tgz\")
	urllib.request.urlretrieve(housing_url, tgz_path)#将URL表示的网络对象复制到本地文件
	housing_tgz = tarfile.open(tgz_path)#打开下载好的文件
	housing_tgz.extractall(path=hosing_path)#解压
	housing_tgz.close()#关闭解压

fetch_housing_data()#调用函数下载数据

下载并显示下载进度

import os 
import sys
import tarfile
from six.moves import urllib
DOWNLOAD_ROOT = \"https://raw.githubusercontent.com/ageron/handson-ml/master/\"
HOUSING_URL = DOWNLOAD_ROOT + HOUSING_PATH + \"/housing.tgz\"

def fetch_housing_data(housing_url=HOUSING_URL, housing_path=HOUSING_PATH):
	if not os.path.isdir(housing_path):
		os.makedirs(housing_url)
	tgz_path = os.path.join(housing_path, \"housing.tgz\")
	def _progress(block_num, block_size, total_size):
		filename = tgz_path.split(\'\\\\\')[-1]
		sys.stdout.write(\'\\r>>Downloading %s %.1f%%\' % (filename, float(block_num*block_size)/float(total_size)*100.0)
		sys.stdout.flush()
	urllib.request.urlretrieve(housing_url, tgz_path)#将URL表示的网络对象复制到本地文件
	housing_tgz = tarfile.open(tgz_path)#打开下载好的文件
	housing_tgz.extractall(path=hosing_path)#解压
	housing_tgz.close()#关闭解压

fetch_housing_data()#调用函数下载数据