[英]reading and manipulating data from a text file in python
我已經做了一個讀取文件並將第一行與其余行分開的函數。 我為此使用的兩個文件是aaa.txt
和bbb.txt
。 我嘗試操縱數據。 我試過平方每個字符串的每個元素,但我意識到我需要浮動它,但我不確定為什么它不會只是浮動。 我哪里出問題了?
aaa.txt
在下面
test a line 1
3,6,8,99,-4,0.6,8
0,9,7,5,7,9,5
2,2,2,2,2,2,5
7,5,1,2,12,8,0.9
=====================
bbb.txt
如下
test b line 1
1,2,3,4,5,6,7,8
55,0,90,09,1,2,3,
8,9,7,6,8,7,6
3,43,5,8,2,4,1
======================
def mi_func(P):
f=open(P, 'r')
first = f.readline()
restlines= f.readlines()
f.close()
return first, restlines
afirst,arest = mi_func('aaa.txt')
bfirst,brest = mi_func('bbb.txt')
print(arest)
print(brest)
##################
#convert a rest into a float here
#convert b rest into a float here
#################
for i in range(len(arest)):
arest[i] = [float(x) for x in arest[i].strip().split(',')]
for i in range(len(brest)):
brest[i] = [float(x) for x in brest[i].strip().split(',')]
p=[i**2 for i in arest] #square each element of a rest
c=[i**2 for i in brest] #square each element of b rest
print(p)
print(c)
['3,6,8,99,-4,0.6,8\n', '0,9,7,5,7,9,5\n', '2,2,2,2,2,2,5\n', '7,5,1,2,12,8,0.9\n']
['1,2,3,4,5,6,7,8\n', '55,0,90,09,1,2,3,\n', '8,9,7,6,8,7,6\n', '3,43,5,8,2,4,1']
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-1-36603657d444> in <module>()
21
22 for i in range(len(brest)):
---> 23 brest[i] = [float(x) for x in brest[i].strip().split(',')]
24
25
<ipython-input-1-36603657d444> in <listcomp>(.0)
21
22 for i in range(len(brest)):
---> 23 brest[i] = [float(x) for x in brest[i].strip().split(',')]
24
25
ValueError: could not convert string to float:
我發現了您的錯誤,似乎您有一些換行符和一些空字符,以及試圖將其強制轉換為浮點數的' 09 '(布雷斯特)
因此,您需要先刪除它們。 對於您的代碼,這只是幾個簡單的調整:
def mi_func(P):
f=open(P, 'r')
first = f.readline()
restlines= f.readlines()
f.close()
return first, restlines
afirst,arest = mi_func('aaa.txt')
bfirst,brest = mi_func('bbb.txt')
#This code will remove leading 0's and split numbers into a list
#while eliminating any standalone new line characters:
arest = [x.lstrip('0').split(',') for x in arest if x != '\n']
brest = [x.lstrip('0').split(',') for x in brest if x != '\n']
for i in range(len(arest)):
arest[i] = [float(x)**2 for x in arest[i] if x != '\n' and x!= '']
print(arest, 'a')
for i in range(len(brest)):
brest[i] = [float(x)**2 for x in brest[i] if x != '\n' and x != '']
print(brest, 'b')
# This is your output
#[[81.0, 49.0, 25.0, 49.0, 81.0, 25.0], [4.0, 4.0, 4.0, 4.0, 4.0, 4.0, 25.0]] a
#[[3025.0, 0.0, 8100.0, 81.0, 1.0, 4.0, 9.0], [64.0, 81.0, 49.0, 36.0, 64.0, 49.0, 36.0]] b
您可以使用此功能從提供的文本文件中返回第一行的浮動列表。
def mi_func(file_name):
with open(file_name) as f:
lines = f.readlines()
float_list = [
float(float_str)
for line in lines[1:]
for float_str in line.strip().split(',')
if float_str != None
]
return lines[0].strip(), float_list
print(mi_func('aaa.txt'))
print(mi_func('bbb.txt'))
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