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argparse

简介​

用来处理入参的模块

基础使用​

引入​

import argparse


if __name__ == "__main__":
    # 初始化实例
    parser = argparse.ArgumentParser()

    # 解释参数
    parser.add_argument(
        "param",   # 不带 -- 定义的是固定位置的必要参数
        help="",
        default="必要参数",
        type=str,
    )
    
    # 解释参数
    parser.add_argument(
        "--param",  # 带 -- 定义的不固定位置的可选参数
        help="【工程前】的流速shp图层文件",
        default="可选参数",
        type=str,
    )

    # 解析成一个对象
    args = parser.parse_args()

位置参数（必要）​




可选参数​


使用案例​

python2.x中调用ArcGis的arcpy模块​

import argparse

parser = argparse.ArgumentParser()
parser.add_argument(
    "before_shp",
    help="【工程前】的流速shp图层文件",
    type=str,
)
parser.add_argument(
    "after_shp",
    help="【工程后】的流速shp图层文件",
    type=str,
)
parser.add_argument(
    "output_shp",
    help="【输出文件名称】最终输出文件的路径，(线文件shp)",
    type=str,
)
parser.add_argument(
    "--river_range",
    help="【面图图层】河道范围，用来明确网点裁剪后的区域",
    type=str,
)
parser.add_argument(
    "--data_field",
    help="流向数据字段名称（角度），在数据文件中的流向字段，字段名，当前要求角度，dfsu文件默认弧度",
    default="speed",
    type=str,
)
parser.add_argument(
    "--limit_length",
    help="忽略长度，默认200，一些长度只有几十的等值线很扰乱视线，建议取100-300的范围作忽略",
    type=int,
    default=200,
)
parser.add_argument(
    "--smooth_value", help="使用PACK算法，这里设定平滑容差", default=30, type=int
)
parser.add_argument("--overwrite", help="是否覆盖输出", action="store_true")

args = parser.parse_args()
main(args.before_shp, args.after_shp, args.output_shp, args.river_range, args)

列表（数组）参数传递​

import argparse
 
parser = argparse.ArgumentParser()
 
# By default it will fail with multiple arguments.
parser.add_argument('--default')
...
# 正确使用
$ python arg.py --default 1234 2345 3456 4567
arg.py: error: unrecognized arguments: 2345 3456 4567
...

# Telling the type to be a list will also fail for multiple arguments,
# but give incorrect results for a single argument.
parser.add_argument('--list-type', type=list)
...
# 错误使用
$ python arg.py --list-type 1234 2345 3456 4567
arg.py: error: unrecognized arguments: 2345 3456 4567
# 正确使用
$ python arg.py --list-type "1234 2345 3456 4567"
['1', '2', '3', '4', ' ', '2', '3', '4', '5', ' ', '3', '4', '5', '6', ' ', '4', '5', '6', '7']
...


# This will allow you to provide multiple arguments, but you will get
# a list of lists which is not desired.
parser.add_argument('--list-type-nargs', type=list, nargs='+')
...
$ python arg.py --list-type-nargs 1234 2345 3456 4567
[['1', '2', '3', '4'], ['2', '3', '4', '5'], ['3', '4', '5', '6'], ['4', '5', '6', '7']]
...

# This is the correct way to handle accepting multiple arguments.
# '+' == 1 or more.
# '*' == 0 or more.
# '?' == 0 or 1.
# An int is an explicit number of arguments to accept.
parser.add_argument('--nargs', nargs='+')
...
$ python arg.py --nargs 1234 2345 3456 4567
['1234', '2345', '3456', '4567']
...

 
# To make the input integers
parser.add_argument('--nargs-int-type', nargs='+', type=int)
...
 $ python arg.py --nargs-int-type 1234 2345 3456 4567
[1234, 2345, 3456, 4567]

 $ python arg.py --nargs-int-type -1234 2345 -3456 4567
[-1234, 2345, -3456, 4567]
...

# An alternate way to accept multiple inputs, but you must
# provide the flag once per input. Of course, you can use
# type=int here if you want.
parser.add_argument('--append-action', action='append')
...
$ python arg.py --append-action 1234 --append-action 2345 --append-action 3456 --append-action 4567
['1234', '2345', '3456', '4567']
...


# To show the results of the given option to screen.
for _, value in parser.parse_args()._get_kwargs():
    if value is not None:
        print(value)