我有一个列表,我知道每种类型的元素[Str, Str, Str, Int, Int, Int, Str, Int]
。我有一个convert函数,可以猜测类型:
def convert(val):
constructors = [int, str]
for c in constructors:
try:
return c(val)
except ValueError:
pass
如何替换convert函数,因为我知道每个元素的类型(请参见下面的完整代码)?你知道吗
from __future__ import absolute_import, division, print_function
from itertools import groupby
DATA = [["Test", "A", "B01", 828288, 1, 7, 'C', 5],
["Test", "A", "B01", 828288, 1, 7, 'T', 6],
["Test", "A", "B01", 171878, 3, 7, 'C', 5],
["Test", "A", "B01", 171878, 3, 7, 'T', 6],
["Test", "A", "B01", 871963, 3, 9, 'A', 5],
["Test", "A", "B01", 871963, 3, 9, 'G', 6],
["Test", "A", "B01", 1932523, 1, 10, 'T', 4],
["Test", "A", "B01", 1932523, 1, 10, 'A', 5],
["Test", "A", "B01", 1932523, 1, 10, 'X', 6],
["Test", "A", "B01", 667214, 1, 14, 'T', 4],
["Test", "A", "B01", 667214, 1, 14, 'G', 5],
["Test", "A", "B01", 667214, 1, 14, 'G', 6]]
def convert(val):
constructors = [int, str]
for c in constructors:
try:
return c(val)
except ValueError:
pass
def main():
with open("/home/mic/tmp/test.txt") as f:
for line in f:
try:
data = [convert(part.strip()) for part in line.split(',')]
print(data)
except IndexError:
continue
更新 感谢您的所有回复,这些回复给了我新的想法,因此我也修改了代码(方法1-4),该代码目前不起作用:
#!/usr/bin/env python
from __future__ import absolute_import, division, print_function
from itertools import groupby
import csv
parts = [["Test", "A", "B01", 828288, 1, 7, 'C', 5],
["Test", "A", "B01", 828288, 1, 7, 'T', 6],
["Test", "A", "B01", 171878, 3, 7, 'C', 5],
["Test", "A", "B01", 171878, 3, 7, 'T', 6],
["Test", "A", "B01", 871963, 3, 9, 'A', 5],
["Test", "A", "B01", 871963, 3, 9, 'G', 6],
["Test", "A", "B01", 1932523, 1, 10, 'T', 4],
["Test", "A", "B01", 1932523, 1, 10, 'A', 5],
["Test", "A", "B01", 1932523, 1, 10, 'X', 6],
["Test", "A", "B01", 667214, 1, 14, 'T', 4],
["Test", "A", "B01", 667214, 1, 14, 'G', 5],
["Test", "A", "B01", 667214, 1, 14, 'G', 6]]
def iter_something(rows):
key_names = ['type', 'name', 'sub_name', 'pos', 's_type', 'x_type']
chr_key_names = ['letter', 'no']
for keys, group in groupby(rows, lambda row: row[:6]):
result = dict(zip(key_names, keys))
result['chr'] = [dict(zip(chr_key_names, row[6:])) for row in group]
yield result
def main():
#Method 1
converters = [str, str, str, int, int, int, str, int]
with open("/home/mic/tmp/test.txt") as f:
parts = (line.strip().split(',') for line in f)
column = (con(part) for con, part in zip(converters, parts))
for object_ in iter_something(column):
print(object_)
#Method 2
with open("/home/mic/tmp/test.txt") as f:
parts = (line.strip().split(',') for line in f)
parts[3], parts[4], parts[5], parts[7] = int(parts[3]),\
int(parts[4]),\
int(parts[5]),\
int(parts[7])
column = (con(part) for con, part in zip(converters, parts))
for object_ in iter_something(column):
print(object_)
#Method 3
converters = [str, str, str, int, int, int, str, int]
with open("/home/mic/tmp/test.txt", 'rb') as f:
reader = csv.reader(f, skipinitialspace=True)
for object_ in iter_something(reader):
print(object_)
#Method 4
with open("/home/mic/tmp/test.txt", 'rb') as f:
reader = csv.reader(f, skipinitialspace=True)
reader[3], reader[4], reader[5], reader[7] = int(reader[3]),\
int(reader[4]),\
int(reader[5]),\
int(reader[7])
for object_ in iter_something(reader):
print(object_)
if __name__ == '__main__':
main()
给定一个
constructors
列表,如您在问题开头所述,您可以这样做:这将为您提供一个二维列表;根据您提供的代码判断,这是您想要的结构。你知道吗
编辑:我修改了解决方案以使用
csv
模块,您需要在顶部导入该模块。上面的代码当然会包含在with
语句中。你知道吗您可以使用
zip()
将类型与列配对:在您的更新中,您再次犯了与您在另一个问题中犯的相同的错误;您在行和列之间产生了混淆,并且正在对行应用该技术:
我是否可以再次考虑使用^{} module ,就像我对你的previous question所做的那样?您在这里稍微重新发明了CSV解析轮:
我会尽力回答你的问题:
由于元素已经是字符串,您只需强制转换int:
所以你的主要想法是:
但由于您已经在使用try,因此最好为ValueError添加一个异常
except (IndexError,ValueError):
您不需要convert函数,在main中强制转换为int就足够了,没有必要强制转换已经是字符串的字符串
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