# 15 个提高效率的 Python 编程技巧

Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.

## 1. 交换值

```x,y=1,2
print(x,y)
x,y=y,x
print(x,y)
```

## 2. 字符串列表合并为一个字符串

```sentence_list = ["my","name","is","George"]
sentence_string =" ".join(sentence_list)
print(sentence_string)
```

## 3. 将字符串拆分为子字符串列表

```sentence_string ="my name is George"
sentence_string.split()
print(sentence_string)
```

## 4. 通过数字填充初始化列表

```[0]*1000# List of1000zeros
[8.2]*1000# List of10008.2's
```

## 5. 字典合并

```x= {'a':1,'b':2}
y= {'b':3,'c':4}
z= {**x, **y}
```

## 6. 反转字符串

```name ="George"
name[::-1]
```

## 7. 从函数返回多个值

```def get_a_string():
a="George"
b ="is"
c ="cool"
returna, b, c
sentence= get_a_string()
(a, b, c) =sentence
```

## 8. 列表解析式

```a= [1,2,3]
b= [num*2for num in a]# Create a new list by multiplying each element in a by 2
```

## 9. 遍历字典

```m = {'a':1,'b':2,'c':3,'d':4}
for key,valueinm.items():
print('{0}: {1}'.format(key,value))
```

## 10. 同时遍历列表的索引和值

```m = ['a','b','c','d']
forindex,valueinenumerate(m):
print('{0}: {1}'.format(index,value))
```

## 11. 初始化空容器

```a_list= list()
a_dict= dict()
a_map= map()
a_set= set()
```

## 12. 删除字符串两端的无用字符

```name =" George "
name_2 ="George///"
name.strip()# prints "George"
name_2.strip("/")# prints "George"
```

## 13. 列表中出现最多的元素

```test = [1,2,3,4,2,2,3,1,4,4,4]
print(max(set(test),key= test.count))
```

## 14. 检查对象的内存使用情况

```import sys
x =1
print(sys.getsizeof(x))
```

## 15. 将 dict 转换为 XML

```fromxml.etree.ElementTreeimportElement
defdict_to_xml(tag, d):
'''
Turn a simple dict of key/value pairs into XML
'''
elem = Element(tag)
forkey, valind.items():
child = Element(key)
child.text = str(val)
elem.append(child)
returnelem
```