字符串连接“\”蟒蛇

Question

我试图串连“\”的路径和文件夹中的文件名，但是当我尝试来连接，我收到EOL同时扫描字符串文字：

path = r"C:\Users\karth\Desktop\udacity\2000" 
add = '\' 
file = os.listdir(path) 
['2000Q1.zip', 
'2000Q2.zip', 
'2000Q3.zip', 
'2000Q4.zip', 
'Acquisition', 
'Performance'] 

print (path+ add + file[0]) 

Answer 1

当您在字符串中使用\'时，它会将'作为字符串的一部分（而不是字尾引号）。 \被称为转义字符。你需要把它写成：

add = '\\' 

按String Literals: Escape Characters文件，下面是所有转义序列与它们的含义的列表：

Escape Sequence  Meaning 
\newline   Ignored 
\\     Backslash (\) 
\'     Single quote (') # <---- Cause of error in your code 
\"     Double quote (") 
\a     ASCII Bell (BEL) 
\b     ASCII Backspace (BS) 
\f     ASCII Formfeed (FF) 
\n     ASCII Linefeed (LF) 
\r     ASCII Carriage Return (CR) 
\t     ASCII Horizontal Tab (TAB) 
\v     ASCII Vertical Tab (VT) 
\uxxxx    Character with 16-bit hex value XXXX (Unicode only (1) 
\Uxxxxxxxx   Character with 32-bit hex value XXXXXXXX (Unicode only) (2) 
\v     ASCII Vertical Tab (VT) 
\ooo    Character with octal value OOO (3,5) 
\xhh    Character with hex value HH (4,5) 

Answer 2

使用os.path.join：

path = r"C:\Users\karth\Desktop\udacity\2000" 
file = os.listdir(path) 

print(os.path.join(path, file[0])) 

或glob.glob以整个路径列出目录：

import glob 
pattern = r"C:\Users\karth\Desktop\udacity\2000\*" 
filenames = glob.glob(pattern) 
print(filenames[0])