如何漂亮在Python中打印CSV文件 [英] How to Pretty Print a CSV file in Python
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问题描述
如何使用Python而不是任何外部工具来打印CSV文件？
How can I pretty print a CSV file using Python, not any external tool?
例如，我有这个CSV文件：
For example I have this CSV file:
title1|title2|title3|title4
datalongdata|datalongdata|data|data
data|data|data|datalongdatadatalongdatadatalongdatadatalongdatadatalongdata
data|data'data|dat
转换它在视觉上看起来像一个表。例如，像这样：
I would like to transform it to visually look like a table. For example, to something like that:
+ --------------------------------------------------------------------------------------------------- +
| title1 | title2 | title3 | title4 |
+ --------------------------------------------------------------------------------------------------- +
| datalongdata | datalongdata | data | data |
| | | | |
| data | data | data | datalongdatadatalongdatadatalongdatadatalongdatadatalongdata |
| data | data'data | dat | |
+ --------------------------------------------------------------------------------------------------- +
推荐答案
pretty.pretty_file（文件名，***选项*）
Usage:
pretty.pretty_file(filename, ***options*)
读取CSV文件，并将数据以表格形式可视化地打印到新文件。 filename 是给定的CSV文件。可选的***选项*关键字参数是Python的标准库 csv 的联合模块方言和格式参数以及以下列表：
Reads a CSV file and prints visually the data as table to a new file. filename, is the given CSV file. The optional ***options* keyword arguments is the union of Python's Standard Library csv module Dialects and Formatting Parameters and the following list:
- new_delimiter ：新的列分隔符（默认|）
- border ：布尔值如果您要打印表格的边框（ default True）
- （ |）
- border_horizontal ：表格的顶部和底部边框默认 - ）
- border_corner_tl ：表格的左上角
- border_corner_tr ：表格的右上角（默认+）
- border_corner_bl ：表格的左下角 border_corner_br ：表格的右下角（默认与 border_corner_tr 相同）
- header ： ： ：：
- border_header_left
- new_delimiter: the new column separator (default " | ")
- border: boolean value if you want to print the border of the table (default True)
- border_vertical_left: the left border of the table (default "| ")
- border_vertical_right: the right border of the table (default " |")
- border_horizontal: the top and bottom border of the table (default "-")
- border_corner_tl: the top-left corner of the table (default "+ ")
- border_corner_tr: the top-right corner of the table (default " +")
- border_corner_bl: the bottom-left corner of the table (default same as border_corner_tl)
- border_corner_br: the bottom-right corner of the table (default same as border_corner_tr)
- header: boolean value if the first row is a table header (default True)
- border_header_separator: the border between the header and the table (default same as border_horizontal)
- border_header_left: the left border of the table header (default same as border_corner_tl)
- border_header_right: the right border of the table header (default same as border_corner_tr)
- new_filename: the new file's filename (default "new_" + filename)
- newline: defines how the rows of the table will be separated (default "\n")
示例：
import pretty_csv
pretty_csv.pretty_file("test.csv", header=False, border=False, delimiter="|")
Python 3：
。对于Python 3，您必须将 open（filename，rb）的2次出现作为输入：更改为在Python 3中， p> csv.reader 在文本模式下需要打开文件
模组：
This is a Python 2 implementation. For Python 3, you have to change the 2 occurrences of the line open(filename, "rb") as input: to open(filename, "r", newline="") as input: since csv.reader in Python 3 wants the file to be opened in text mode.
import csv
def pretty_file(filename, **options):
"""
@summary:
Reads a CSV file and prints visually the data as table to a new file.
@param filename:
is the path to the given CSV file.
@param **options:
the union of Python's Standard Library csv module Dialects and Formatting Parameters and the following list:
@param new_delimiter:
the new column separator (default " | ")
@param border:
boolean value if you want to print the border of the table (default True)
@param border_vertical_left:
the left border of the table (default "| ")
@param border_vertical_right:
the right border of the table (default " |")
@param border_horizontal:
the top and bottom border of the table (default "-")
@param border_corner_tl:
the top-left corner of the table (default "+ ")
@param border_corner_tr:
the top-right corner of the table (default " +")
@param border_corner_bl:
the bottom-left corner of the table (default same as border_corner_tl)
@param border_corner_br:
the bottom-right corner of the table (default same as border_corner_tr)
@param header:
boolean value if the first row is a table header (default True)
@param border_header_separator:
the border between the header and the table (default same as border_horizontal)
@param border_header_left:
the left border of the table header (default same as border_corner_tl)
@param border_header_right:
the right border of the table header (default same as border_corner_tr)
@param newline:
defines how the rows of the table will be separated (default "\n")
@param new_filename:
the new file's filename (*default* "/new_" + filename)
"""
#function specific options
new_delimiter = options.pop("new_delimiter", " | ")
border = options.pop("border", True)
border_vertical_left = options.pop("border_vertical_left", "| ")
border_vertical_right = options.pop("border_vertical_right", " |")
border_horizontal = options.pop("border_horizontal", "-")
border_corner_tl = options.pop("border_corner_tl", "+ ")
border_corner_tr = options.pop("border_corner_tr", " +")
border_corner_bl = options.pop("border_corner_bl", border_corner_tl)
border_corner_br = options.pop("border_corner_br", border_corner_tr)
header = options.pop("header", True)
border_header_separator = options.pop("border_header_separator", border_horizontal)
border_header_left = options.pop("border_header_left", border_corner_tl)
border_header_right = options.pop("border_header_right", border_corner_tr)
newline = options.pop("newline", "\n")
file_path = filename.split(os.sep)
old_filename = file_path[-1]
new_filename = options.pop("new_filename", "new_" + old_filename)
column_max_width = {} #key:column number, the max width of each column
num_rows = 0 #the number of rows
with open(filename, "rb") as input: #parse the file and determine the width of each column
reader=csv.reader(input, **options)
for row in reader:
num_rows += 1
for col_number, column in enumerate(row):
width = len(column)
try:
if width > column_max_width[col_number]:
column_max_width[col_number] = width
except KeyError:
column_max_width[col_number] = width
max_columns = max(column_max_width.keys()) + 1 #the max number of columns (having rows with different number of columns is no problem)
if max_columns > 1:
total_length = sum(column_max_width.values()) + len(new_delimiter) * (max_columns - 1)
left = border_vertical_left if border is True else ""
right = border_vertical_right if border is True else ""
left_header = border_header_left if border is True else ""
right_header = border_header_right if border is True else ""
with open(filename, "rb") as input:
reader=csv.reader(input, **options)
with open(new_filename, "w") as output:
for row_number, row in enumerate(reader):
max_index = len(row) - 1
for index in range(max_columns):
if index > max_index:
row.append(' ' * column_max_width[index]) #append empty columns
else:
diff = column_max_width[index] - len(row[index])
row[index] = row[index] + ' ' * diff #append spaces to fit the max width
if row_number==0 and border is True: #draw top border
output.write(border_corner_tl + border_horizontal * total_length + border_corner_tr + newline)
output.write(left + new_delimiter.join(row) + right + newline) #print the new row
if row_number==0 and header is True: #draw header's separator
output.write(left_header + border_header_separator * total_length + right_header + newline)
if row_number==num_rows-1 and border is True: #draw bottom border
output.write(border_corner_bl + border_horizontal * total_length + border_corner_br)
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