add 2.3-2.6

Author: xxg1413

Chapter2/Chapter2.py

@@ -65,11 +65,105 @@ def ch2_3():
     print(data_file)
 
 
+def ch2_4():
+    '''
+    2.4 文本模式的匹配和查找
+    使用正则
+    '''
+
+    print("\nch2_4:")
+
+    text1 = "02/11/2017"
+    text2 = "02/11/2017 tomorrow is 02/12/2017"
+
+    import  re
+    if re.match(r"\d+/\d+/\d+", text1):
+        print("yes")
+    else:
+        print("no")
+
+    date_p = re.compile(r"\d+/\d+/\d+")
+    if date_p.match(text1):
+        print("yes")
+    else:
+        print("no")
+
+    result = date_p.findall(text2)
+    print(result)
+
+    #增加捕获组  多次匹配或者查找，建议先编译
+    date_p = re.compile(r"(\d+)/(\d+)/(\d+)")
+    result  = date_p.findall(text2)
+    for month,day, year in result:
+        print("{}-{}-{}".format(year,month,day))
+
+
+def ch2_5():
+    '''
+    2.5 对字符串中的文本做查找和替换
+
+    '''
+
+    print("\nch2_5:")
+
+    text1 ="Today is 02/11/2017, 春节是02/26/2017"
+
+    import re
+
+    #先匹配，后替换
+    result = re.sub(r"(\d+)/(\d+)/(\d+)",r"\3-\1-\2", text1)
+    print(result)
+
+    data_p = re.compile(r"(\d+)/(\d+)/(\d+)")
+
+    from calendar import  month_abbr
+
+    def change_date(m):
+        mon_name = month_abbr[int(m.group(1))]
+        return '{} {} {}'.format(m.group(2),mon_name,m.group(3))
+
+    result,count = data_p.subn(change_date, text1)
+    print("结果:",result, "\n总共替换:", count)
+
+
+
+def ch2_6():
+    '''
+    2.6 以不区分大小写的方式对文本做检查和替换
+    使用re.IGNORECASE
+    '''
+    print("\nch2_6:")
+
+    text = "UPPER PYTHON, lower python, Mixed Python"
+
+    import  re
+    result = re.findall(r"python", text, flags=re.IGNORECASE)
+    print(result)
+
+    #替换成相同的格式
+    result = re.sub("python", "snake", text, flags=re.IGNORECASE)
+    print(result)  #注意snake是全部小写
+
+    def matchcase(word):
+        def replace(m):
+            text = m.group()
+            if text.isupper():
+                return word.upper()
+            elif text.islower():
+                return word.lower()
+            elif text[0].isupper():
+                return  word.capitalize()
+            else:
+                return word
+        return  replace
+
+    result = re.sub("python", matchcase("snake"), text, flags=re.IGNORECASE)
+    print(result)
 
 
 def main():
 
-    for i in range(1,4):
+    for i in range(1,7):
         func='ch2_%d()'%(i)
         exec(func)