Tag: string slicing Python

1. What is a string? A string is a sequence of characters used to store text. medicine_name = "Paracetamol" dosage_form = "Tablet" batch_number = "TAB-2026-015" storage_instruction = "Store below 25°C" The quotation marks tell Python that the value is text. ValueData typeMeaning"500"strText containing digits500intWhole number"25.5"strDecimal written as text25.5floatDecimal number 2. Why do we use string manipulation? Pharmaceutical records contain text that may be entered inconsistently: " paraCETamol " "PARACETAMOL" "paracetamol" "Paracetamol" Although these appear similar to a person, Python treats them as different strings. String manipulation helps us: Remove unnecessary spaces. Standardise capitalisation. Search medicine descriptions. Separate batch-code sections. Validate whether required fields are present. Prepare readable labels. Create inventory summaries. Standardise imported text data. 3. Important string operations OperationSyntaxPurposeCreate stringname = "Paracetamol"Store textLengthlen(name)Count charactersIndexingname[0]Retrieve one characterSlicingname[0:4]Retrieve several charactersConcatenationtext1 + text2Join stringsRepetition"-" * 20Repeat textLowercase.lower()Convert to lowercaseUppercase.upper()Convert to uppercaseTitle case.title()Capitalise wordsRemove spaces.strip()Clean both endsReplace.replace()Replace selected textSearch.find()Find first positionCount.count()Count occurrencesMembershipin, not inCheck text presencePrefix check.startswith()Check beginningSuffix check.endswith()Check endingSplit.split()Divide text into partsJoin.join()Combine text partsAlphabet check.isalpha()Check for lettersDigit check.isdigit()Check for digitsAlphanumeric check.isalnum()Check letters and digitsFormatted textf-stringInsert variables into text 4. Indexing and slicing Python starts counting characters from zero. For the word PHARMA: CharacterPHARMAPositive index012345Negative index-6-5-4-3-2-1 word = "PHARMA" print(word[0]) # P print(word[-1]) # A print(word[0:3]) # PHA print(word[::-1]) # AMRAHP The stop position in a slice is excluded. Therefore, [0:3] returns positions 0, 1 and 2. Pharmacy application batch_code = "TAB-2026-015" product_prefix = batch_code[0:3] year_section = batch_code[4:8] sequence_number = batch_code[9:12] print(product_prefix) print(year_section) print(sequence_number) Output: TAB 2026 015 This extracts visible sections but does not confirm that the batch exists. 5. Cleaning medicine names raw_medicine_name = " paraCETamol " clean_medicine_name = raw_medicine_name.strip().title() print("Original:", repr(raw_medicine_name)) print("Cleaned:", clean_medicine_name) Output: Original: ' paraCETamol ' Cleaned: Paracetamol Interpretation .strip() removes spaces from both ends. .title() standardises capitalisation. repr() makes hidden external spaces visible. The result is more consistent, but Python has not verified its spelling or identity against approved medicine master data. 6. Searching label text label_text = "Paracetamol 500 mg Tablet" print("Tablet" in label_text) print("Syrup" not in label_text) print(label_text.find("500 mg")) print(label_text.count("Paracetamol")) Output: True True 12 1 Interpretation "Tablet" in label_text checks whether the exact text is present. "Syrup" not in label_text confirms that the word is absent. .find() returns the starting position. .count() reports the number of exact occurrences. These operations are case-sensitive. 7. Splitting pharmaceutical records medicine_record = "Paracetamol|500 mg|Tablet|TAB-015" record_parts = medicine_record.split("|") print("Medicine:", record_parts[0]) print("Strength:", record_parts[1]) print("Dosage form:", record_parts[2]) print("Batch:", record_parts[3]) Output: Medicine: Paracetamol Strength: 500 mg Dosage form: Tablet Batch: TAB-015 .split("|") separates the text wherever the vertical bar appears. To join the parts again: readable_record = " - ".join(record_parts) print(readable_record) 8. String validation methods batch_code = "TAB-2026-015" parts = batch_code.split("-") prefix = parts[0] year_text = parts[1] sequence_text = parts[2] print("Prefix contains letters:", prefix.isalpha()) print("Year contains digits:", year_text.isdigit()) print("Sequence contains digits:", sequence_text.isdigit()) Output: Prefix contains letters: True Year contains digits: True Sequence contains digits: True This validates only the visible pattern: letters-digits-digits It does not authenticate the batch through a manufacturing database. 9. Formatted output using f-strings medicine_name = "Cetirizine" strength_mg = 10 dosage_form = "Tablet" batch_number = "CTZ-026" label = ( f"{medicine_name} {strength_mg} mg " f"{dosage_form} | Batch: {batch_number}" ) print(label) Output: Cetirizine 10 mg Tablet | Batch: CTZ-026 F-strings are usually easier to understand than repeatedly using +. 10. String immutability Strings are immutable. This means an existing string cannot be changed character by character. raw_name = "paracetamol" clean_name = raw_name.title() print(raw_name) print(clean_name) Output: paracetamol Paracetamol .title() created and returned a new string. The original string remained unchanged. 11. Pharmaceutical-industry applications AreaApplicationInventoryStandardising medicine namesManufacturingSeparating visible batch-code sectionsQuality controlFormatting sample summariesPackagingPreparing prototype label textWarehousingChecking location-code prefixesDocumentationDetecting blank mandatory fieldsData cleaningReplacing inconsistent delimitersReportingCreating readable output using f-stringsPharmacovigilance preparationStandardising text categories before expert review String operations improve consistency, searchability, and presentation. They do not establish medicine quality, safety, identity, efficacy, or regulatory compliance. Dr. Arpana Chaturvedi HOD -IT , Associate Professor (Department of IT and Data ANalytics/AI ML)

Tag: string slicing Python

Python String Operations – Basic Manipulation Techniques

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