File: detsv.py 1 #!/usr/bin/python3 2 3 # The MIT License (MIT) 4 # 5 # Copyright © 2024 pacman64 6 # 7 # Permission is hereby granted, free of charge, to any person obtaining a copy 8 # of this software and associated documentation files (the “Software”), to deal 9 # in the Software without restriction, including without limitation the rights 10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 # copies of the Software, and to permit persons to whom the Software is 12 # furnished to do so, subject to the following conditions: 13 # 14 # The above copyright notice and this permission notice shall be included in 15 # all copies or substantial portions of the Software. 16 # 17 # THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 # SOFTWARE. 24 25 26 from json import dumps 27 from math import isinf, isnan 28 from sys import argv, exit, stderr, stdin, stdout 29 from typing import Any 30 31 32 info = ''' 33 detsv [options...] [filepath/URI...] 34 35 36 DE-TSV turns a TSV-format (Tab-Separated Values) table into other common 37 data formats, like JSON (JavaScript Object Notation), or `JSONS` (JSON 38 Strings). 39 40 The output is JSONS by default, since keeping the original input-data as 41 strings can't accidentally mangle values. 42 43 All (optional) leading options start with either single or double-dash, 44 and most of them change the style/color used. Some of the options are, 45 shown in their single-dash form: 46 47 -h show this help message 48 -help show this help message 49 50 -j convert into JSON, parsing numbers, and using null for empty 51 -json convert into JSON, parsing numbers, and using null for empty 52 53 -jsons convert into JSON Strings, where values are strings or null 54 -json-s convert into JSON Strings, where values are strings or null 55 ''' 56 57 # handle standard help cmd-line options, quitting right away in that case 58 if len(argv) == 2 and argv[1] in ('-h', '--h', '-help', '--help'): 59 print(info.strip()) 60 exit(0) 61 62 63 def narrow_value(s: str) -> Any: 64 # empty strings become null values 65 if s == '': 66 return None 67 68 # try parsing valid floating-point values 69 try: 70 f = float(s) 71 if not (isnan(f) or isinf(f)): 72 return f 73 except Exception: 74 pass 75 76 # can't narrow/parse the string, so keep it as is 77 return s 78 79 80 def to_json(w, src, narrow = narrow_value) -> None: 81 try: 82 line = next(src) 83 line = line.rstrip('\r\n').rstrip('\n').split('\t') 84 header = line 85 except Exception: 86 # not even a header line 87 w.write('[]\n') 88 return 89 90 # prepare row-holder dictionary 91 kv = {} 92 for s in header: 93 kv[s] = None 94 95 n = 0 96 for line in src: 97 row = line.rstrip('\r\n').rstrip('\n').split('\t') 98 w.write(',\n ' if n > 0 else '[\n ') 99 100 # don't forget to reset values from previous row 101 for s in header: 102 kv[s] = None 103 # update values up to what the current row gives 104 for j, s in enumerate(row): 105 kv[header[j]] = narrow(s) 106 107 w.write(dumps(kv)) 108 n += 1 109 110 # don't forget to close top-level array 111 w.write('[]\n' if n == 0 else '\n]\n') 112 113 114 def to_jsons(w, src) -> None: 115 return to_json(w, src, lambda s: s) 116 117 118 def to_tsv(w, src) -> None: 119 for line in src: 120 row = line.rstrip('\r\n').rstrip('\n').split('\t') 121 for i, s in enumerate(row): 122 if i > 0: 123 w.write('\t') 124 w.write(s) 125 w.write('\n') 126 127 128 def seems_url(s: str) -> bool: 129 protocols = ('https://', 'http://', 'file://', 'ftp://', 'data:') 130 return any(s.startswith(p) for p in protocols) 131 132 133 def handle_input(w, r, outfmt: str) -> None: 134 fmt2handler = { 135 'json': to_json, 136 'jsons': to_jsons, 137 } 138 139 if outfmt in fmt2handler: 140 fmt2handler[outfmt](w, r) 141 else: 142 raise ValueError(f'unsupported output format {outfmt}') 143 144 145 # fmt_names normalizes output-format names, and even has `self-aliases`, 146 # so a membership check also checks if a name is supported 147 fmt_names = { 148 'j': 'json', 149 'json': 'json', 150 151 'jsons': 'jsons', 152 'jsonstr': 'jsons', 153 'jsonstrings': 'jsons', 154 'json-s': 'jsons', 155 'json-str': 'jsons', 156 'json-strings': 'jsons', 157 } 158 159 args = argv[1:] 160 # default output format is JSONS, since it can't accidentally mangle data 161 out_format = fmt_names['jsons'] 162 163 # handle leading output-format option, if present 164 if len(args) > 0 and args[0].startswith('-'): 165 s = args[0].lstrip('-').lower() 166 if s in fmt_names: 167 out_format = fmt_names[s] 168 # skip leading arg, since it's clearly not a filepath 169 args = args[1:] 170 171 try: 172 if len(args) == 0: 173 path = '-' 174 elif len(args) == 1: 175 path = args[0] 176 else: 177 raise ValueError('multiple inputs not allowed') 178 179 if path == '-': 180 handle_input(stdout, stdin, out_format) 181 elif seems_url(path): 182 from io import TextIOWrapper 183 from urllib.request import urlopen 184 with urlopen(path) as inp: 185 # can't use byte-sources directly during string-processing 186 with TextIOWrapper(inp, encoding='utf-8') as txt: 187 handle_input(stdout, txt.readlines(), out_format) 188 else: 189 with open(path, encoding='utf-8') as inp: 190 handle_input(stdout, inp, out_format) 191 except BrokenPipeError: 192 # quit quietly, instead of showing a confusing error message 193 stderr.close() 194 except KeyboardInterrupt: 195 exit(2) 196 except Exception as e: 197 print(f'\x1b[31m{e}\x1b[0m', file=stderr) 198 exit(1)