trying to rewrite my R function in python #33
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scripts/sql-ing-lookup.py
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| sql_query_start_l3 = "INNER JOIN dmd.ing as ing ON ing.id = vpi.ing\n" | ||
| sql_query_start_l4 = "LEFT JOIN dmd.ddd on vmp.id = ddd.vpid\n" | ||
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| sql_query_start = sql_query_start_l1 + sql_query_start_l2 + sql_query_start_l3 + sql_query_start_l4 |
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why 4 strings joined rather than 1 string?
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Agreed. The names of these variables don't help me understand why they are different. If they are, then also consider using an f-string:
first_name = "Dizzee"
last_name = "Rascal"
full_name = f"{first_name} {last_name}" # "Dizzee Rascal"
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Given none of that is parameterised I'd be inclined to write it as a triple-quoted multiline string
sql_query_start = """
SELECT
'vmp' AS type,
CAST(vmp.id AS STRING) AS id,
bnf_code,
vmp.nm,
ing.nm AS ingredient,
ddd.ddd
FROM dmd.vmp"
scripts/sql-ing-lookup.py
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| ingredient_list = [f"{ingredient}%" for ingredient in ingredient_list] | ||
| elif wildcards == "both": | ||
| ingredient_list = [f"%{ingredient}%" for ingredient in ingredient_list] | ||
| elif wildcards == "none": |
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Could have the default as None rather than a string and then no need to do anything here
scripts/sql-ing-lookup.py
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| return sql_query_return | ||
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| #%% |
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sql_query_where = "WHERE " + " OR ".join([f"{sql_str_lower_01}ing.nm{sql_str_lower_02} LIKE {ing}" for ing in ingredient_list] ?
scripts/sql-ing-lookup.py
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| @@ -0,0 +1,80 @@ | |||
| #%% | |||
| # Define function to query details for ingredients | |||
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Could this be part of the docstring?
scripts/sql-ing-lookup.py
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| sql_query_where = [] | ||
| sql_query_or = list() | ||
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| # For loop writing WHERE and OR statements |
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If no wildcards, could use SQL IN here. To do this I normally convert list to tuple and then use an f-string, e.g.
# convert list to tuple for use in SQL query
names_tuple = tuple(names)
if len(names_tuple)==1:
# remove comma if only one item
names_tuple = str(names_tuple).replace(",","")
sql = f'WHERE ingredient IN {names_tuple}'
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or ",".join(ingredient_list) handles the case where there is only one item in a list more concisely.
scripts/sql-ing-lookup.py
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| raise ValueError('Second argument "wildcards" should be one of: "prefix", "suffix", "both", "none') | ||
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| # Define empty objects for loop | ||
| sql_query_where = [] |
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I think this will just be a string so no need to define it here first?
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Underscores rather than hyphens in the filename would make it more consistent with the other scripts |
just an example function that writes SQL using python. although the code works it's slightly out of date and I mainly started this to practice my python skills.