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python - Python递归与for循环

问题描述

我想用 Python 处理一些文件并有以下脚本：

import pandas as pd
loc1 = r'D:\1103\DC431.txt'
loc2 = r'D:\1103\DC432.txt'
loc3 = r'D:\1103\DC433.txt'
loc4 = r'D:\1103\DC434.txt'
loc5 = r'D:\1103\DC435.txt'
loc6 = r'D:\1103\DC436.txt'
loc7 = r'D:\1103\DC437.txt'
# Start
df1 = pd.read_table(loc1, sep=('\t'), engine='python')
df2 = pd.read_table(loc2, sep=('\t'), engine='python')
df3 = pd.read_table(loc3, sep=('\t'), engine='python')
df4 = pd.read_table(loc4, sep=('\t'), engine='python')
df5 = pd.read_table(loc5, sep=('\t'), engine='python')
df6 = pd.read_table(loc6, sep=('\t'), engine='python')
df7 = pd.read_table(loc7, sep=('\t'), engine='python')

s1 = df1[df1['No (Int)'] == 4]
s2 = df2[df2['No (Int)'] == 4]
s3 = df3[df3['No (Int)'] == 4]
s4 = df4[df4['No (Int)'] == 4]
s5 = df5[df5['No (Int)'] == 4]
s6 = df6[df6['No (Int)'] == 4]
s7 = df7[df7['No (Int)'] == 4]
# End

# Other scripts

我试图使用 for 循环简化上述开始到结束之间的脚本，但 python 无法识别：

for n in range (1,8):
    dfn = pd.read_table(locn, sep=('\t'), engine='python')
    sn = dfn[dfn['No (Int)'] == 4]

有人有好的想法吗？

标签： pythonfor-looprecursion

解决方案

dfn并且sn是变量名称，python 不知道您的意思是 index n。您可以改用列表。首先没有列表理解：

import pandas as pd

locs = []
dfs = []
ss = []

for i in range(1, 8):
    locs[i] = r'D:\1103\DC43{}.txt'.format(i)
    dfs[i] = pd.read_csv(locs[i], sep='\t')
    ss[i] = dfs[i][dfs[i]['No (Int)'] == 4

使用列表理解：

import pandas as pd

locs = [r'D:\1103\DC43{}.txt'.format(i) for i in range(1,8)]
dfs = [pd.read_csv(loc, sep='\t') for loc in locs]
ss = [df[df['No (Int)'] == 4] for df in dfs]

笔记：

  • pandas.read_table已弃用，取而代之的是pandas.read_csv.
  • C 引擎可能就足够了，只有在需要时才添加 python 引擎。

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