python - 使用多个if条件时如何克服ValueError？

我正在尝试制作一个可以识别文件夹名称是否为项目的脚本。为此，我想使用多个if条件。但是，我很难处理例如检查文件夹名称的首字母和是否为数字所导致的ValueError。如果它是字符串，我想跳过该文件夹并检查下一个文件夹。预先感谢大家的帮助。
干杯，本恩

我尝试了While和ValueError除外：但是还没有成功。

＃将项目的正确名称命名为“ YYMM_ProjectName” =“ 1908_Sample_Project”

projectnames = ['190511_Waldfee', 'Mountain_Shooting_Test', '1806_Coffe_Prime_Now', '180410_Fotos', '191110', '1901_Rollercoaster_Vision_Ride', 'Musicvideo_LA', '1_Project_Win', '19_Wrong_Project', '1903_di_2', '1907_DL_2', '3401_CAR_Wagon']

＃检查条件

for projectname in projectnames:
    if int(str(projectname[0])) < 3 and int(projectname[1]) > 5 and ((int(projectname[2]) * 10) + int(projectname[3])) <= 12 and str(projectname[4]) == "_" and projectname[5].isupper():
        print('Real Project')
        print('%s is a real Project' % projectname)
        # print("Skipped Folders")

ValueError：int（）以10为底的无效文字：“ E”

最佳答案

根据我对所有if的了解，...实际上使用regex匹配可能会更好。您正在解析每个字符，并期望每个单独的字符都在非常有限的字符范围内。

我尚未测试此模式字符串，因此它可能不正确或需要根据您的需要进行调整。

import re

projectnames = ['1911_Waldfee', "1908_Project_Test", "1912_WinterProject", "1702_Stockfootage", "1805_Branded_Content"]

p = ''.join(["^", # Start of string being matched
             "[0-2]", # First character a number 0 through 2 (less than 3)
             "[6-9]", # Second character a number 6 through 9 (single digit greater than 5)
             "(0(?=[0-9])|1(?=[0-2]))", # (lookahead) A 0 followed only by any number 0 through 9 **OR** A 1 followed only by any number 0 through 2
             "((?<=0)[1-9]|(?<=1)[0-2])", # (lookbehind) Match 1-9 if the preceding character was a 0, match 0-2 if the preceding was a 1
             "_", # Next char is a "_"
             "[A-Z]", #Next char (only) is an upper A through Z
              ".*$" # Match anything until end of string
    ])

for projectname in projectnames:
    if re.match(p, projectname):
        #print('Real Project')
        print('%s is a real Project' % projectname)
        # print("Skipped Folders")

编辑：=======================

您可以使用以下步骤逐步测试模式...

projectname = "2612_UPPER"
p = "^[0-2].*$" # The first character is between 0 through 2, and anything else afterwards
if re.match(p, projectname): print(projectname)
# If you get a print, the first character match is right.
# Now do the next
p = "^[0-2][6-9].*$" # The first character is between 0 through 2, the second between 6 and 9, and anything else afterwards
if re.match(p, projectname): print(projectname)
# If you get a print, the first and second character match is right.
# continue with the third, fourth, etc.

关于python - 使用多个if条件时如何克服ValueError？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/58382568/