Python使用指南 | 实战匠坊

Python是一种高级编程语言，以其简洁、易读、易学的语法和广泛的应用场景而闻名。

随着AI技术的平民化，很有必要掌握该门语言

配置pip

bash

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py

python get-pip.py

镜像加速：

-i https://pypi.tuna.tsinghua.edu.cn/simple

配置Jupyter

bash

jupyter notebook --generate-config --allow-root

jupyter notebook password

#配置 jupyter_notebook_config.py
c.NotebookApp.ip='*'
c.NotebookApp.password = u'sha:ce...刚才复制的那个密文'
c.NotebookApp.open_browser = False
c.NotebookApp.port =9998 #可自行指定一个端口, 访问时使用该端口

启动服务

bash

jupyter notebook --allow-root

测试

http://locahost:9998/tree?

数据类型

查看更多: https://t.zsxq.com/uC6Pm

常用API

拷贝字符串到剪贴板

python

import pyperclip
pyperclip.copy(imgLink)

pip install pyperclip

获取当前用户的下载目录

python

import ctypes.wintypes

def getDocPath(pathID=5):
    '''path=5: My Documents'''
    buf= ctypes.create_unicode_buffer(ctypes.wintypes.MAX_PATH)
    ctypes.windll.shell32.SHGetFolderPathW(None, pathID, None, 0, buf)
    return buf.value
downloadPath = os.path.join(os.path.dirname(getDocPath(0)),"Downloads")
print(downloadPath)

C:\Users\wangx\Downloads

获取主机名

python

os.popen('hostname').read().replace("\n","")

DESKTOP-7O54MHN

函数

main函数

python

if __name__ =="__main__":
    #相当于执行pytest test_xxx.py命令
    pytest.main(["test_xxxx.py"])

if __name__=="__main__"

该语句主要判断代码是从该.py文件直接运行，还是被其他文件导入或调用后才运行

name__是Python内置变量，存放了当前的模块名称。当模块直接运行时，模块名为__main。

如果从该.py文件直接运行（例如在调试时，就直接从当前文件运行），就会执行pytest测试，执行的文件名称为test_xxx.py。

高阶函数

高阶：参数是函数、返回值是函数

常见的高阶函数：map、reduce、filter、apply

apply 在 Python2.3 被移除，reduce 被放在 functools 包中

推导式和生成器表达式可以替代 map 和 filter 函数

map(函数，序列) 将序列中每个值传入函数，处理完成返回为 map 对象

python

number = list(range(11))
def square(x):
    return x**2
    print(list(map(square, number)))
    print(dir(map(square, number)))

filter(函数，序列)将序列中每个值传入函数，符合函数条件的返回为 filter 对象

时间函数

获取当前时间戳(天)

python

import time
def get_today():
    now = int(time.time())
    timeArray = time.localtime(now)
    today = time.strftime("%Y-%m-%d", timeArray)
    # print (today)
    return today

2022-12-03

获取当前时间戳(秒)

python

import time
def get_ts():
    now = int(time.time())
    timeArray = time.localtime(now)
    ts = time.strftime("%Y%m%d%H%M%S", timeArray)
    print (ts)
    return ts

20221203225816

python

import time
def get_ts():
    now = int(time.time())
    timeArray = time.localtime(now)
    ts = time.strftime("%Y-%m-%d %H:%M:%S", timeArray)
    print (ts)
    return ts

2022-12-03 22:58:16

文件处理

七牛云sdk上传指定文件夹：https://t.zsxq.com/gdgE7

下载文件

python

url = sys.argv[1]
r = requests.get(url)
localfile = os.path.basename(url)
with open(localfile, "wb") as f:
    f.write(r.content)

压缩打包

python

import zipfile
import os

class ZipHelper:
    def __init__(self):
        self.file_count = 0

    def zip_dir(self,dirname,zipfilename):
        filecount = 0
        filelist = []
        if os.path.isfile(dirname):
            filelist.append(dirname)
        else :
            for root, dirs, files in os.walk(dirname):
                for name in files:
                    filelist.append(os.path.join(root, name))

        zf = zipfile.ZipFile(zipfilename, "w", zipfile.zlib.DEFLATED)
        for tar in filelist:
            arcname = tar[len(dirname):]
            print ("package >>",arcname)
            zf.write(tar,arcname)
            self.file_count += 1
        zf.close()


# zip_helper = ZipHelper()
# zip_helper.zip_dir("./","test.zip")
# print(os.path.getsize("test.zip"))

读写xlsx

python

from openpyxl  import load_workbook

class Excel_XLSX:
    def __init__(self,filepath):
        self.filepath = filepath
        self.wb = load_workbook(self.filepath)
        self.ws = self.wb['Sheet1']

    def read(self):
        for row in self.ws.rows:
            for cell in row:
                print(row, cell.value)

    def change_data(self,columns,values):
        rows = self.ws.max_row+1
        for index in range(len(columns)):
            key = str(columns[index]) + str(rows)
            self.ws[key] = str(values[index])

    # 是否有id
    def is_exists(self,item_id):
        for row in self.ws.rows:
            row_values = []
            for cell in row:
                row_values.append(cell.value)
            if item_id in row_values:
                return True
        return False

    def save(self):
        self.wb.save(self.filepath)

if __name__ == '__main__':
    excel_xlsx = Excel_XLSX('upload_list.xlsx')
    excel_xlsx.change_data(['A','B','C','D'],["100","作品名称",'照片名称','拍摄时间','照片路径'])
    print(excel_xlsx.is_exists("xxxxx产品1-1"))
    # excel_xlsx.save()

读xls

python

import xlrd
xls_path = "xxxx.xls"
data = xlrd.open_workbook(xls_path)
table = data.sheet_by_index(0)
nrows = table.nrows
for rowx in range(1,nrows):
	imageName = table.row(rowx)[0].value

读写pdf

python

import pdfminer
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfpage import PDFPage, PDFTextExtractionNotAllowed
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.pdfdevice import PDFDevice
from pdfminer.layout import LAParams
from pdfminer.converter import PDFPageAggregator


fp = open('xxxx.pdf', 'rb')

# Create a PDF parser object associated with the file object
parser = PDFParser(fp)

# Create a PDF document object that stores the document structure.
# Password for initialization as 2nd parameter
document = PDFDocument(parser)
# Check if the document allows text extraction. If not, abort.
if not document.is_extractable:
    raise PDFTextExtractionNotAllowed

# Create a PDF resource manager object that stores shared resources.
rsrcmgr = PDFResourceManager()

# Create a PDF device object.
#device = PDFDevice(rsrcmgr)

# BEGIN LAYOUT ANALYSIS.
# Set parameters for analysis.
laparams = LAParams(
    char_margin=10.0,
    line_margin=0.2,
    boxes_flow=0.2,
    all_texts=False,
)
# Create a PDF page aggregator object.
device = PDFPageAggregator(rsrcmgr, laparams=laparams)
# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)

# loop over all pages in the document
for page in PDFPage.create_pages(document):
    # read the page into a layout object
    interpreter.process_page(page)
    layout = device.get_result()
    for obj in layout._objs:
        if isinstance(obj, pdfminer.layout.LTTextBoxHorizontal):
            print(obj.get_text().replace("\n",""))

多媒体处理

修改微信小程序二维码logo：https://t.zsxq.com/EChp1

生成视频序列帧:https://t.zsxq.com/EXyTF

基于kokoro实现tts:https://t.zsxq.com/7BdHk

操作数据库

操作mysql: https://t.zsxq.com/ddQAq

异步编程

bash

pip install aiohttp hypercorn asgiref

查看代码：https://gitee.com/PatrickW/flask-web/blob/master/src/case8_async/app.py

Flask

配置pip ​

配置Jupyter ​

数据类型 ​

常用API ​

函数 ​

main函数 ​

高阶函数 ​

时间函数 ​

获取当前时间戳(天) ​

获取当前时间戳(秒) ​

文件处理 ​

下载文件 ​

压缩打包 ​

读写xlsx ​

读xls ​

读写pdf ​

多媒体处理 ​

操作数据库 ​

异步编程 ​

Flask ​

配置pip

配置Jupyter

数据类型

常用API

函数

main函数

高阶函数

时间函数

获取当前时间戳(天)

获取当前时间戳(秒)

文件处理

下载文件

压缩打包

读写xlsx

读xls

读写pdf

多媒体处理

操作数据库

异步编程

Flask