with+open('u.data')+as+f1: list+= with+open('u_new.data',+)+as+f2: for+line+in+list: values+=+line.s
时间: 2023-12-25 22:05:56 浏览: 25
很抱歉,您的问题不太清楚。但是,我可以根据您提供的引用内容为您解释一下Python中的文件操作和字符串操作。
文件操作:
1. 打开文件并写入内容,使用'a'模式可以将内容添加到文件末尾而不是覆盖之前的内容。
```python
f = open('test.txt', 'a')
f.write('hello, world!')
f.close()
```
2. 使用with语句打开多个文件进行操作,可以避免手动关闭文件。
```python
with open('file1.txt', 'r') as f1, open('file2.txt', 'r') as f2:
for line1 in f1:
line2 = f2.readline()
# do something with line1 and line2
```
字符串操作:
1. 将字符串添加到列表中,可以使用列表的append()方法。
```python
my_list = ['apple', 'banana']
my_list.append('orange')
print(my_list) # 输出:['apple', 'banana', 'orange']
```
2. 使用strip()方法删除字符串开头和结尾的空格和换行符。
```python
my_string = ' hello, world! \n'
my_string = my_string.strip()
print(my_string) # 输出:'hello, world!'
```
相关问题
import os # 第一步:创建目录 dir_name = "fibonacci" if not os.path.exists(dir_name): os.mkdir(dir_name) # 第二步:将斐波那契数列的前1000个数据写入文件fib_data.txt print("正在将斐波那契数列的前1000个数据写入文件...") fib_list = [0, 1] for i in range(2, 1000): fib_list.append(fib_list[i-1] + fib_list[i-2]) with open(os.path.join(dir_name, "fib_data.txt"), "w") as f: for i, num in enumerate(fib_list): f.write("第 {} 个数是:{}\n".format(i+1, num+1)) print("完成!") print("fib_data 已保存") # 第三步:截取fib_data.txt文件的第899-920行,并写入新文件fib_part_data.txt print("正在截取数据...") with open(os.path.join(dir_name, "fib_data.txt"), "r") as f1: lines = f1.readlines() with open(os.path.join(dir_name, "fib_part_data"), "w") as f2: for line in lines[898:919]: f2.write(line) print("完成!") print("fib_part_data 已保存") # 第四步:显示fib_part_data.txt文件内容 with open(os.path.join(dir_name, "fib_part_data.txt"), "r") as f: print(f.read())截取的切片怎么隔一行输出一行
要让截取的内容每行隔一行输出,可以在写入新文件 fib_part_data.txt 时,每写入一行数据后再写入一个空行即可。修改代码如下:
```
print("正在截取数据...")
with open(os.path.join(dir_name, "fib_data.txt"), "r") as f1:
lines = f1.readlines()
with open(os.path.join(dir_name, "fib_part_data.txt"), "w") as f2:
for i, line in enumerate(lines[898:919]):
f2.write(line)
if i % 2 == 0: # 每隔一行写入一个空行
f2.write("\n")
print("完成!")
print("fib_part_data 已保存")
# 第四步:显示fib_part_data.txt文件内容
with open(os.path.join(dir_name, "fib_part_data.txt"), "r") as f:
print(f.read())
```
这样就可以实现每行隔一行输出了。
import datetime import pandas as pd def generate_figure(user_name): with open('./data/orders.txt','r') as f1: orders = [eval(each.strip()) for each in f1.readlines()] users_order = [user for user in orders if user['username'] == user_name] order_list = [] with open('./data/produts.txt','r') as f2: products = [eval(product.strip()) for product in f2.readlines()] for item in users_order: user_all_orders = {} user_all_orders['month'] = datetime.datetime.strftime(datetime.datetime.strptime(item['create_time'],"%Y-%m-%d_%H:%M:%S"),"%B") user_all_orders['pro_id'] = item['pro_id'] user_all_orders['pro_price'] = ''.join([str(each['pro_current_price']) for each in products if each['pro_id'] == item['pro_id']]) order_list.append(user_all_orders) df_orders = pd.DataFrame(order_list)这段代码中我该怎么写才能让df_orders变成group by month并且显示的是该月份消费的proprice的总和
你可以使用 Pandas 中的 `groupby()` 和 `sum()` 函数来实现按月份分组并计算每月的 `proprice` 总和的操作,具体代码如下:
```python
import datetime
import pandas as pd
def generate_figure(user_name):
with open('./data/orders.txt', 'r') as f1:
orders = [eval(each.strip()) for each in f1.readlines()]
users_order = [user for user in orders if user['username'] == user_name]
order_list = []
with open('./data/produts.txt', 'r') as f2:
products = [eval(product.strip()) for product in f2.readlines()]
for item in users_order:
user_all_orders = {}
user_all_orders['month'] = datetime.datetime.strftime(datetime.datetime.strptime(item['create_time'], "%Y-%m-%d_%H:%M:%S"), "%B")
user_all_orders['pro_id'] = item['pro_id']
user_all_orders['pro_price'] = ''.join([str(each['pro_current_price']) for each in products if each['pro_id'] == item['pro_id']])
order_list.append(user_all_orders)
df_orders = pd.DataFrame(order_list)
df_orders['pro_price'] = pd.to_numeric(df_orders['pro_price'])
df_monthly_spending = df_orders.groupby(['month'])['pro_price'].sum()
return df_monthly_spending
```
在这个代码中,我们首先将 `pro_price` 转换为数字类型,然后使用 `groupby()` 函数按照 `month` 列进行分组,最后使用 `sum()` 函数计算每个月份的 `pro_price` 总和。