Some usage of Python is Shared

1) the use of regular expressions.

 
# Regular expression modules  
import re 
# Regular expression  
rePattern = '.*[0-9]{4}' 
pattern = re.compile(rePattern) 
# matching  
if pattern.match(line): 
return True 
else: 
return False 

2) use global variables in functions.

 
def func(): 
global num 

3)python default print output newline.
If you need to output without breaking a line, add a comma at the end.

 
print 'Hello World!', 

4) sharding of strings.
Split () is used according to a string, and the default parameter is whitespace, including Spaces, carriage returns, tabs, etc. :
StrList = STRS. Split (' _ ')
If you need to shred by multiple strings, you can use regular expressions:

 
# Shards by Spaces and horizontal tabs  
strList = re.split("[ts]", strs) 

5) determine if a string is a number.

 
if str.isdigit(): 
return True 
else: 
return False 

6) read and write files

 
# Read the file  
fin = file('1.txt', 'r') 
# Write files  
fout = file('1_ans.txt', 'w') 
while True: 
line = fin.readline() 
# At the end of file  
if len(line)==0: 
break 
fout.write(line) 
fin.close() 
fout.close() 

7) use of lists

 
ansList = [] 
# Increases the value in the list  
ansList.append('Hello1') 
ansList.append('Hello2') 
# Sort the list  
ansList.sort() 
# Traverse the output  
for ans in ansList 
print ans